IWARA2018 - 8th International Workshop on Astronomy and Relativistic Astrophysics

Contribution List

130. Inka Astronomy

Milton Rojas Gamarra (Physics Department, Faculty of Science, UNSAAC)

08/09/2018, 17:10

Talk

The Inkas had their own "Science", in all areas of knowledge. In this contribution, we will present their ancestral knowledge which refers to Astronomy, mainly we will present its constellations. This study is based on the triangulation of the chronicles, oral tradition and the complexes and archaeological elements that we can still locate.

4. Cosmology of the Incas

Steven Gullberg (University of Oklahoma)

08/09/2018, 17:40

Talk

The Incas worshipped the Sun, with light and shadow effects in their constructs commonly denoting such events as the solstices and equinoxes. They as well honored and venerated many features of both natural and man-made landscapes that they felt to be endowed with superhuman powers. In Quechua, these shrines were known as huacas, and at the time of the Spanish conquest there were thousands of...

14. Thermodynamics of noncommutative black holes

Eri Mena (Universidad de Guadalajara)

09/09/2018, 09:00

Talk

We study the noncommutative formalism for black holes and their thermodynamics properties in the classical and quantum scenarios.

80. Some remarks on black holes with fluid of strings: solutions, thermodynamics and Hawking radiation

Geusa Marques (Universidade Federal de Campina Grande)

09/09/2018, 09:15

Talk

In the early 1980´s, Letelier introduced a gauge invariant model of a fluid of strings with the aim to treat gravity coupled to these array of strings, in the framework of general relativity. Thus, using the fluid formed by strings as a source of the gravitational field, he obtained a solution of the Einstein equations corresponding to a spherically symmetric space-time. In the case of...

30. Particle motion analysis in a regular black hole solution

Katharine Ivette Cuba Quispe (Universidad Nacional de Trujillo, Universidad Privada del Norte)

09/09/2018, 09:30

Talk

The main goal of this work is to analyze the motion of diferent types of particles in a regular black hole solution obtained by Bronnikov in 2001. The trajectories are obtained through numerical integration of the equations of the orbits (using the program Maple), after the analysis of the effective potential of each case. The results are compared to those of the Reissner-Nordstrom black hole....

41. Non-linear perturbation of black branes at large D

Umpei Miyamoto (Akita Prefectural University)

09/09/2018, 09:50

Talk

The Einstein equations describing the black-brane dynamics both in Minkowski and AdS background were recently recast in the form of coupled diffusion equations in the large-$D$(imension) limit. Using such results in the literature, we formulate a higher-order perturbation theory of black branes in time domain and present the general form of solutions for arbitrary initial conditions. For...

10. Evolution of stellar binaries from supermassive black hole binaries

Ye-Fei Yuan (University of Science and Technology of China)

09/09/2018, 10:10

Talk

The evolution of main-sequence binaries resided in the galactic centre is influenced a lot by the central supermassive black hole (SMBH). Due to this perturbation, the stars in a dense environment are likely to experience mergers or collisions through secular or non-secular interactions. In this work, we study the dynamics of the stellar binaries at galactic centre, perturbed by another...

99. Study of white dwarfs, neutron stars and black holes through astrometric microlensing

Kailash Sahu (Space Telescope Science Institute)

09/09/2018, 10:50

Talk

Astrometric microlensing provides a powerful tool to study white dwarfs, neutron stars and black holes, particularly the isolated ones. We have two such projects to study stellar remnants through astrometric microlensing, the details of which will be discussed: (i) In a reprise of the famous 1919 solar eclipse experiment that confirmed Einstein's general theory of relativity, the nearby white...

66. Oscillations of black hole accretion disks and neutron star atmospheres

Wlodek Kluzniak (Copernicus Astronomical Center)

09/09/2018, 11:10

Talk

Quasi-periodic oscillations (QPOs) in the kHz range have been reported in the X-ray flux of several accreting black hole and neutron star systems. While several models have been suggested, such variability has been difficult to reproduce in numerical simulations. I will report on Radiative General Relativistic Hydrodynamic Simulations of accretion disks in which several high-frequency...

91. Black holes binaries from globular clusters as sources of gravitational waves

Dorota Rosinska (University of Zielona Gora)

09/09/2018, 11:30

Talk

The direct detection of gravitational waves from binary black hole mergers by the advanced Laser Interferometer Gravitational-Wave Observatories has ushered astrophysics into a new era of observing cosmic events that were previously invisible. Using results for around two thousand star cluster models simulated using well-tested the MOCCA Monte Carlo code for star cluster evolution we...

104. Probing astrophysical black holes via gravitational lensing

Q. Daniel Wang (University of Massachusetts)

09/09/2018, 11:50

Talk

Black holes (BHs) represent the most extreme objects in the universe and play an important role in astrophysics. We have been exploring various ideas of using gravitational lensing to probe the population and astrophysics of BHs. Supermassive BHs of million solar masses or greater are usually detected as active galactic nuclei (AGN). We show that the innermost X-ray-emitting structure of AGN...

122. Nucleus 3-flavored

Renxin Xu (Peking University)

09/09/2018, 12:10

Talk

Normal nuclei inside atoms are 2-flavored. What if normal baryonic matter is compressed intensely by gravity so that a huge number of nuclei would gradually merge to form a gigantic nucleus? It is proposed that gigantic nuclei could be 3-flavored, to be manifested in the form of compact stars, cosmic rays, and even dark matter.

109. Relativistic corrections to large scale structures

Clement Stahl (PUCV)

09/09/2018, 14:00

Talk

We investigate the relativistic corrections to the standard model of formation of large scale structures. In matter domination and in the Poisson gauge, we use the weak-field approximation which allows to keep compact expressions even for the one-loop bispectrum. Whereas in the Newtonian limit, the choice of gauge is marginally important as all gauge coincides, when relativistic corrections...

120. Magnetic field effect on the effective potential of a heavy charged scalar field

Angel Sanchez Cecilio (Facultad de Ciencias, Universidad Nacional Autónoma de México)

09/09/2018, 14:15

Talk

In the context of a warm inflation scenario in this work we study the effects of a primordial magnetic field on the effective potential of a heavy charged scalar field in a magnetized thermal bath. It is known that models, based on global supersymmetry with a new-inflation-type potential and a coupling between the inflaton and a heavy intermediate superfield, preserve the flatness required...

38. Infinite nuclear matter characteristics of finite nuclei within relativistic mean field formalism

Mrutunjaya Bhuyan (Instituto Tecnologico de Aeronautica)

09/09/2018, 14:30

Talk

The present study establishes a correlation between the neutron skin thickness and the infinite nuclear matter characteristics for the even−even isotopes of Fe, Ni, Zn, Ge, Se, and Kr. The axially deformed self-consistent relativistic mean field for the non-linear NL3$^*$ is used for the analysis. The coherent density functional method is adopted to formulate the symmetry energy, the neutron...

126. Strongly interacting matter under intense magnetic fields

Norberto Scoccola (Comisión Nacional de Energía Atómica)

09/09/2018, 14:50

Talk

Different aspects of the behavior of quark and hadronic matter under intense magnetic fields are analyzed within the framework of Nambu-Jona-Lasinio models.

16. Equations of boson-fermion star and the basic equation discussions under Newtonian approximation

Zhifu Gao (Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 150, Science 1-Street, Urumqi, Xinjiang 830011, China)

09/09/2018, 15:10

Talk

There is accumulating evidence that scalar fields may exist in nature. The gravitational collapse of a boson cloud would lead to the formation of a boson star just like white dwarfs and neutron star. In generally, as one of candidates of dark matter, a boson star holds a stable configuration and has deserved intensive attention and extensive researches in the past 50 years. At first, we...

96. Testing black-hole near-horizon effects and pseudo-complex general relativity with gravitational waves

Alex Nielsen (Max Planck Institute for Gravitational Physics (AEI))

09/09/2018, 15:30

Talk

The detection of gravitation waves by LIGO has allowed a great number of new tests of strong gravity and near-horizon models for black holes. One such model, pseudo-complex general relativity, agrees with Einstein gravity in the weak-field limit, but diverges dramatically in the near-horizon regime, with certain parameter ranges excluding the existence of black holes altogether. We show how...

19. Numerical analysis of the Biermann battery mechanism of magnetogenesis for relativistic MHD turbulence

David Garrison (University of Houston Clear Lake)

09/09/2018, 15:50

Talk

We present the results of Relativistic Magnetohydrodynamic simulations utilizing a range of initial conditions in order to see if seed magnetic fields may be generated via the Biermann battery mechanism of magnetogenesis. These simulations occur in a simulated early universe around the time of the electroweak era ${10}^{-11}$ seconds after the Big Bang. Our results are characterized by the...

123. Equation of state at finite chemical potential, based on the PNJL Lagrangian

Joerg Aichelin (Subatech/CNRS)

09/09/2018, 16:30

Talk

The NJL and PNJL approach had problems to describe the lattice equation of state for zero chemical potential. This made this Lagrangian, despite of its great merits, less attractive to study what happens for a finite baryon chemcial potential. A finite baryon chemical potential is expected for the experiments at FAIR/Germany and NICA, Russia but also during the merger of two neutron stars...

106. Electromagnetic probes of QGP

Elena Bratkovskaya (FIAS)

09/09/2018, 16:50

Talk

Dileptons are considered as one of the cleanest signals of the quark-gluon plasma (QGP), however, the QGP radiation is masked by many 'background' sources from either hadronic decays or semileptonic decays from correlated charm pairs.
We investigated the relative contribution of these channels in heavy-ion collisions from $\sqrt{s_{\rm NN}}=$ 8 GeV to 5 TeV with a focus on the competition...

97. The Athena X-ray observatory

Giorgio Matt (Dipartimento di Matematica e Fisica, Universita' Roma Tre)

10/09/2018, 09:00

Talk

Athena (the Advanced Telescope for High-Energy Astrophysics) will continue the series of large X-ray observatories inaugurated by Chandra and XMM-Newton, offering transformational capabilities in several key areas. It is the second large-class ESA mission (L2), and it is planned for a launch towards the end of the next decade.
In this talk, the main science objectives of Athena, and its main...

58. The imaging X-ray Polarimetry Explorer

Giorgio Matt (Dipartimento di Matematica e Fisica, Universita' Roma Tre)

10/09/2018, 09:15

Talk

IXPE, the Imaging X-ray Polarimetry Explorer, has been selected by NASA on January 2017 as the next mission in the Small Explorer Program, for a launch in early 2021. IXPE, a collaboration between NASA and ASI (the Italian Space Agency), is led by M. Weisskopf (MSFC) and is composed by three identical telescopes with, at the focal plane, a Gax Pixel Detector based on the photoelectric effect....

49. Observation of ultra-high-energy cosmic rays with the Telescope Array experiment

Kazumasa Kawata

10/09/2018, 09:30

Talk

The Telescope Array (TA) is the largest ultra-high-energy cosmic-ray (UHECR) detector in the northern hemisphere, which consists of 507 surface detector covering a total 700 km^2 and three fluorescence detector stations. In this presentation, we will discuss our recent results on the UHECR energy spectrum, mass composition and anisotropy based on the latest dataset collected by the Telescope...

70. The X-Ray Astronomy Recovery Mission

Brian Williams (NASA GSFC)

10/09/2018, 09:50

Talk

The X-Ray Astronomy Recovery Mission (XARM), an international collaboration led by JAXA and involving major participation from NASA and ESA, will employ an advanced X-ray observatory with capabilities to carry out a science program to address some of the important questions of present-day astrophysics. XARM is essentially a rebuild of the the Hitomi (Astro-H) spacecraft that was lost due to an...

76. Exploring the structure of neutron stars in low-mass X-ray binaries

Dany Page (Universidad Nacional Autonoma de Mexico)

10/09/2018, 10:10

Talk

Transient low-mass X-ray binaries containing a neutron star which sporadically accrete matter from a low-mass companion provide a unique opportunity to study the internal structure of neutron stars. During accretion phase the neutron star is heated and driven out of thermal equilibrium. During the following quiescent phase, when no accretion is occurring, the thermal relaxation of the neutron...

52. Relativistic X-ray jets at high redshift

Dan Schwartz (Smithsonian Astrophysical Observatory)

10/09/2018, 10:50

Talk

Powerful radio sources and quasars emit relativistic jets of plasma and magnetic fields that travel hundreds of kilo-parsecs, ultimately depositing energy into the external medium. In the rest frame of the jet, the energy density of the cosmic microwave background is enhanced by the bulk Lorentz factor as $\Gamma^2$, and when this exceeds the magnetic energy density the primary loss mechanism...

73. Fermi/GBM’s key role at the dawn of the era of multimessenger astronomy

Andreas von Kienlin (MPE)

10/09/2018, 11:10

Talk

The detection of the gravitational wave event GW170817 by LIGO and Virgo was accompanied by the independent detection of the short Gamma-ray Burst GRB 170817A by the Gamma-ray Burst Monitor (GBM) of NASA’s Fermi mission. This discovery was complemented by the detection of a weak coincident signal in the data of the Anti-Coincidence Shield ACS of Spectrometer SPI onboard ESA’s INTEGRAL mission....

87. The 4 meter New Robotic Telescope

Carlos Gutierrez (Instituto de Astrofisica de Canarias)

10/09/2018, 11:30

Talk

The time domain astronomy will radically change in the coming decade, with the advent of facilities like LSST, SKA, CTA, etc that will find huge numbers of transients across the electromagnetic spectrum, and with the detections via non-electromagnetic signals, such as gravitational waves. Within this context, we plan to build the New Robotic Telescope (NRT), a 4 m optical and near infrared...

54. Probing the universe at the highest energies with the Pierre Auger Observatory

Jakub Vicha (Institute of Physics of the Czech Academy of Sciences)

10/09/2018, 11:50

Talk

The Pierre Auger Observatory is the currently largest cosmic-ray detector covering ultra-high energies from 10$^{18}$ eV to 10$^{20}$ eV. The size of exposure accumulated since 2004 granted measurements of unprecedented precisions on energy spectrum, mass composition and anisotropy searches. These measurements guide us slowly to the sources of ultra-high energy cosmic rays, which is a...

67. High-precision cosmology from the Sloan Digital Sky Survey

Alexander Mayer (N/A)

10/09/2018, 12:10

Talk

Analysis of galaxy redshift data and theta-z data from the Sloan Digital Sky Survey (SDSS) provides surprising new insights in cosmology, which overturn prior results.

111. Characterization of orbits for the MacMillan problem with test particle of variable mass

Edgar Andrés Acosta Pinzón (Universidad Industrial de Santander)

10/09/2018, 14:00

Talk

In the present study, we conduct a numerical analysis of the MacMillan problem in which the mass of the test particle varies in time according to the Jeans’ law. The MacMillan problem is a particular case of the circular three body problem, where the third body moves along an axis passing through the center of mass of the system, and is perpendicular to the plane of the primaries. Since the...

72. Classical features of polynomial higher-derivative gravities

Breno Giacchini (Centro Brasileiro de Pesquisas Físicas)

10/09/2018, 14:15

Talk

Local gravitational theories with more than four derivatives have remarkable quantum properties. Namely, they are super-renormalizable and may be unitary in the Lee-Wick sense, if the massive poles of the propagator are complex. It is important, therefore, to explore also the IR limit of these theories and identify possible observable signatures of the higher derivatives. In this talk we...

11. Merger of two compact stars: predictions from the two-families scenario

Giuseppe Pagliara

10/09/2018, 14:30

Talk

The detection of GW170817 and its electromagnetic counterparts has marked the beginning of multi-messenger astrophysics which could allow, in the near future, to finally establish which is the internal composition of neutron stars. I will discuss what we have learned from this first binary neutron star GW's detection on the equation of state in particular concerning the possibility of having...

69. The primordial B-modes search in the CMB polarization with LSPE/SWIPE

Fabio Columbro (Sapienza, University of Rome)

10/09/2018, 14:50

Talk

Measurements of the cosmic microwave background (CMB) polarization represent the best technique to study physical phenomena happening a split-second within the big bang and to test the standard cosmological model. In this scenario, the Large-Scale Polarization Explorer (LSPE) aims at the measurement of polarization at the largest angular scales, where cosmic inflation left its imprint in the...

64. Reconstruction of large-scale CMB temperature anisotropies with primordial CMB induced in galaxy cluster

Guo Chin Liu (Tamkang University)

10/09/2018, 15:10

Talk

Scattering of cosmic microwave background radiation in galaxy clusters induces polarization signals determined by the quadrupole anisotropy in the photon distribution at the location of clusters. This remote quadrupole derived from the measurements of the induced polarization in galaxy clusters provides the information of local CMB temperature anisotropies. Here we present an algorithm of the...

86. Time-domain astrophysics of galactic nuclei in radio to submillimeter

Q. Daniel Wang (University of Massachusetts)

10/09/2018, 15:30

Talk

I will review ideas as to how a joint monitoring program at radio to submillimeter wavelengths may be used to study the relativistic jet formation and circumnuclear environment of supermassive black holes. At least some tidal disruption events (TDE) of (sub-)stellar objects around black holes form relativistic jets. Such a jet can first be detected in (sub)millimeter and only gradually become...

117. Cosmological mass transport on galactic nuclei and the growth of high z quasars

Andres Escala Astorquiza (Universidad de Chile)

10/09/2018, 15:50

Talk

By using AMR cosmological hydrodynamic N-body zoom-in simulations, with the RAMSES code, we studied the mass transport processes onto galactic nuclei from high redshift up to $z\sim 6$. Due to the large dynamical range of the simulations we were able to study the mass accretion process on scales from $\sim 50$ kpc to $\sim$ pc. The SMBHs are modelled as a sink particles at the center of our...

129. Magnetic field effect on the decay process of a neutral scalar boson

Gabriella Piccinelli Bocchi (Universidad Nacional Autónoma de México)

10/09/2018, 16:30

Talk

The effect of a homogeneous weak magnetic field on the decay process of a neutral scalar field to a pair of charged fermions is studied. The decay rate is calculated through the imaginary part of the self-energy of the scalar particle interacting with the charged fermions, at one loop. We find that the effect depends on the kinematical regime of the progenitor particle: for low transverse...

140. Observational constraints on the NS equation of state

Zhaosheng Li (Department of Physics, Xiangtan University, China)

10/09/2018, 16:50

Talk

The measurement of neutron star mass and radius is one of the most direct ways to distinguish between various dense matter equations of state. The mass and radius of accreting neutron stars hosted in low-mass X-ray binaries can be constrained by several methods, including photospheric radius expansion from type I X-ray bursts, gravitational redshift measurement and from quiescent spectra. In...

60. Unification of strongly magnetized neutron stars with regard to X-ray emission from hot spots

Tomokage Yoneyama (Osaka University)

11/09/2018, 09:00

Talk

Strongly magnetized isolated neutron stars (NSs) are categorised into two families, according mainly to their magnetic field strength. The one with a higher magnetic field of $10^{14}$ - $10^{15}$ Gauss is called “magnetar”, and the other is the X-ray isolated neutron star (XINS) with $10^{13}$ Gauss. Both magnetars and XINSs show thermal emission in X-rays, whose spectra are different. The...

74. The high time resolution universe survey for pulsars

Marilyn Cruces (Max-Planck Institute for Radioastronomy)

11/09/2018, 09:15

Talk

Abstract:

Pulsars are neutron stars, detected mainly through the pulses of electromagnetic radiation emitted from their poles, which is modulated by their stable rotation. Since their discovery in 1967 they have become fundamental tools for understanding subject such as stellar evolution, theories of gravity, the electron content of our Galaxy and understanding the behavior of matter at...

15. Investigations of the Ohmic decay and the soft X-ray emission of high-braking index pulsar PSR J1640$-$4631

Zhifu Gao (Xinjiang Astronomical Observatory, Chinese Academy of Sciences, 150, Science 1-Street, Urumqi, Xinjiang 830011, China)

11/09/2018, 09:30

Talk

In this work, we investigate the Ohmic decay of surface dipole magnetic field of high-braking index pulsar PSR J1640$-$4631, and interpret the observed soft X-ray flux $F_{x}^{\infty}[2-10\rm keV]$ from $Chandra +NuStar$ telescopes. We obtain the ohmic decay timescale $\tau_{\rm ohm}\sim 3.23\times10^{6}$ yr. Observations indicate that magnetic multipole fields could exist in a neutron star...

48. Anti-correlation between X-ray luminosity and pulsed fraction in the Small Magellanic Cloud pulsar SXP 1323

Jun Yang (University of Utah)

11/09/2018, 09:50

Talk

We report the evidence for the anti-correlation between pulsed fraction (PF) and luminosity of the X-ray pulsar SXP 1323, found for the first time in a luminosity range $10^{35}$--$10^{37}$ erg s$^{-1}$ from observations spanning 15 years. The phenomenon of a decrease in X-ray PF when the source flux increases has been observed in our pipeline analysis of other X-ray pulsars in the Small...

77. Pions near condensation under compact star conditions

Cristian Villavicencio (Universidad del Bio-Bio)

11/09/2018, 10:10

Talk

The behavior of pions is studied in systems where their normal leptonic decay is forbidden. When thermal fluctuations are present, a low decay rate is generated, and as a consequence of lepton recombination, the amount of pions remains almost unaltered. Compact stars conditions are favorable for the formation of such intermediate state of charged pions: near condensation and almost stable,...

65. Electron-positron pair creation in pulsars

Andrey Timokhin (NASA/GSFC)

11/09/2018, 10:50

Talk

Pulsars are among the most extreme objects in the universe, where physical processes work in regimes of extreme densities as well as gravitational and electromagnetic field strengths. It is widely agreed upon that pulsar activity is intimately connected to the copious generation of electron-positron pairs in the magnetosphere - a rapidly rotating magnetized neutron star is active as pulsar...

108. Cooling of small and massive hyperonic stars

Rodrigo Negreiros (Universidade Federal Fluminense)

11/09/2018, 11:10

Talk

We perform cooling simulations for isolated neutron stars using recently developed equations of state for their core. The equations of state are obtained from new parametrizations of the FSU2 relativistic mean-field functional that reproduce the properties of nuclear matter and finite nuclei, while fulfilling the restrictions on high-density matter deduced from heavy-ion collisions,...

93. Was GW170817 indeed a merger of two neutron stars?

David Blaschke (University of Wroclaw)

11/09/2018, 11:30

Talk

The merger of two compact stars is the celebrated event in Astrophysics which provides highest baryon densities and temperatures simultaneously as well as compact objects at the limit of stability, most likely in a transition stage to a black hole which, triggered by a gravitational wave signal, is then observable in all wavelengths of the electromagnetic spectrum, in some cases also in...

95. Properties of hypothetical quark-hadron lattices in the cores of neutron stars

Fridolin Weber (Department of Physics, San Diego State University and Center for Astrophysics and Space Sciences, University of California, San Diego)

11/09/2018, 11:50

Talk

In this talk, we investigate the effect a crystalline quark-hadron mixed phase can have on the neutrino emissivity from the cores of neutron stars. To this end we use relativistic mean-field equations of state to model hadronic matter and a nonlocal extension of the three-flavor Nambu-Jona-Lasinio model for quark matter. The extent of the quark-hadron mixed phase and its crystalline structure...

37. The evolving story of pulsar wind nebulae

Patrick Slane

11/09/2018, 12:10

Talk

The expanding winds generated by pulsars produce nebulae whose properties track both the composition and energetics of the winds and the properties of the environments into which they expand. From early expansion through cold supernova ejecta, through re-formation after disruption from interactions with the supernova remnant reverse shock, the evolution of a pulsar wind nebula is complex....

42. Can loop quantum cosmology describe an unified and consistent scenario since bounce until the end of inflation?

Eunice Valtânia de Jesus Bezerra (Instituto Nacional de Pesquisas Espaciais (INPE))

11/09/2018, 14:00

Talk

The inflationary model was introduced by Guth in the 80's as a way of solving the so-called three cosmological problems: flatness of the space-time, the problem of the horizon, and the question of the magnetic monopoles. Since it was proposed, inflation has become much more than a cosmological model. The inflationary period may perhaps give us some clues about the transition from a continuum...

101. Correlations functions of primordial perturbations from symmetries

Josué Motoa-Manzano (Universidad del Valle)

11/09/2018, 14:15

Talk

In this work we use the correspondence between a field theory in de Sitter space in 4-dimensions and the dual conformal field theory in an euclidean space in 3-dimensions to constraint the form of correlation functions of primordial perturbations. To this end, we use an inflationary model, in which the inflaton field is interacting with a vector field trough the term $f1(\phi)F_{μ\nu} F^{μ\nu}...

31. Magnetars: Pi in the sky?

Nayasinganahalli Hari Dass (TIFR Hyderabad)

11/09/2018, 14:30

Talk

Abstract: Magnetars are incredible astrophysical objects with the largest ever observed magnetic fiels that are more than a thousand times larger than Pulsar magnetic fields.They are also associated with some of the most powerful flares ever seen. The origin of such strong magnetic fields is a fascinating problem in physics. I shall describe in this talk work done with V. Soni, with earlier...

51. Lethal radiation from nearby supernovae helps to explain the small cosmological constant

Tomonori Totani (Univ. of Tokyo)

11/09/2018, 14:50

Talk

The observed value $\Lambda_{obs}$ of the cosmological constant $\Lambda$ is extremely smaller than theoretical expectations, and the anthropic argument has been proposed as a solution to this problem because galaxies do not form when $\Lambda \gg \Lambda_{obs}$. However, the contemporary galaxy formation theory predicts that stars form even with a high value of $\Lambda / \Lambda_{obs} \sim...

50. Progenitor mass distribution of core-collapse supernova remnants in our galaxy and Magellanic Clouds

Satoru Katsuda (Saitama University)

11/09/2018, 15:10

Talk

We investigate a progenitor mass distribution of core-collapse supernova remnants (CCSNRs) in our Galaxy and the Large and Small Magellanic Clouds, for the first time. We use the zero-age main-sequence mass, $M_{\rm ZAMS}$, estimated from elemental abundances and count the number of the CCSNRs in three mass ranges:
A: $M_{\rm ZAMS} < 15\ {\rm M}_\odot$,
B: $15\ {\rm M}\odot < M{\rm ZAMS}...

21. Magnetorotational instability in supernova explosion

Sergey Moiseenko (Space Research Institute)

11/09/2018, 15:30

Talk

We represent results of numerical simulation of magnetorotational (MR) instability which develops in MR core-collapsed supernova explosion. The MR instability leads to the exponential growth of all components of the magnetic field. It significantly reduce the time for the development of MR exlosion. The MR instability is of Tayler type with rotation. The maximal values of magnetic field found...

119. Mergers and GRBs: past, present and future

Tsvi Piran (The Hebrew University)

11/09/2018, 15:50

Talk

The observed GRB (170817A) that followed GW170817 confirmed the longstanding prediction of association of short GRBs with neutron star mergers. The unique large scale observational campaign that followed provided numerous surprising observations. I discuss past predictions concerning binary mergers. I then turn to current observations of GW 170817 and its EM counterpart and their...

114. Neutrinos from SN1987A: temperature models for two neutrinos’ bursts

Rodolfo Valentim (Unifesp - Diadema)

11/09/2018, 16:30

Talk

The neutrinos’ burst from SN1987A were detected on different experiments around the World on February in 1987 until today it is theme of discussions and re-analysis. All events were approximately twenty five in the following detectors: Kamiokande II (KII) in Japan ~ 12, Irvine-Michigan-Brookhaven (IMB) in USA~8 and Baksan in Soviet Union ~ 5. The neutrinos play a key role on cooling mechanism...

118. Searching for baryon number violation with neutrino experiments

Jennifer Raaf (Fermi National Accelerator Laboratory)

11/09/2018, 16:50

Talk

The observation of a violation of baryon number conservation would have tremendous impact and implications for the fields of particle and astrophysics and cosmology. Observation of baryon number violating processes such as proton decay or neutron-antineutron oscillation would point to grand unification of the EM, strong, and weak forces at very high energies. This talk will present the...

17. Everything you were eager to know about information relativity theory (but were afraid to ask)

Ramzi Suleiman (Triangle Center for Research & Decvelopment)

13/09/2018, 09:00

Talk

Information Relativity Theory is a simple, axiom-free, epistemic relativizing of Newtonian physics. It attempts to answer the following question: What information will a proper measurement device in laboratory A, register about an occurrence in another laboratory B, which is in a state of motion relative to A. We assume that information about the respective occurrence (e.g., the start, and...

25. Celestial tidal effect on clock comparison

Yujie Tan (Huazhong University of Science & Technology)

13/09/2018, 09:15

Talk

With the rapid development of the clock technology, the unprecedented accuracy and stability provides a potential to measure the solar gravitational redshift with the clock-comparison experiments in the laboratory. The clock-comparison model is discussed in both the Barycentric Celestial Reference System (BCRS) and the Geocentric Celestial Reference System (GCRS), in which the transformations...

26. Experimental design and progress for testing Lorentz symmetry in gravity

Chenggang Shao (Huazhong University of Science & Technology)

13/09/2018, 09:30

Talk

Local Lorentz invariance (LLI) is an important component of General Relativity (GR). The test of LLI can not only probe the foundation stone of GR, but also help to explore the physics beyond GR and Standard Model. In the previous work, we have limited the LLI coefficients with the gravitational experiments (gravitational inverse square law) performed in our lab. As the Lorentz-violation...

82. Gravity waves speed in the non-Abelian Galileon vector theory

Yeinzon Rodriguez Garcia (UAN & UIS (Colombia))

13/09/2018, 09:50

Talk

Galileon theories are built with the purpose of having the most general scalar-tensor theory free of the Ostrogradski instability. Quite recently, the vector Galileon theories have been formulated, in particular its non-Abelian version (invariance under a global SU(2) symmetry). The theory, together with a cosmic triad configuration, is able to reproduce the present dark energy epoch,...

103. The galaxy center with scalar field dark matter (ultra-light boson) haloes

Tonatiuh Matos (Cinvestav IPN, México)

13/09/2018, 10:10

Talk

Recent analysis of the rotation curves of a large sample of galaxies with very diverse stellar properties reveal a relation between the radial acceleration purely due to the baryonic matter and the one inferred directly from the observed rotation curves. Assuming the dark matter (DM) exists, this acceleration relation is tantamount to an acceleration relation between DM and baryons. This leads...

1. Inflation, dark energy and dark matter in supergravity

Sergei Ketov (Tokyo Metropolitan University and Kavli IPMU)

13/09/2018, 10:50

Talk

We review some recent developments in describing cosmological inflation, dark energy, dark matter and primordial black holes in supergravity. Their relations to string cosmology on the one side, and to reheating after inflation, on the other side, are also outlined. Open problems of the theory are emphasised too.

Literature: our papers in arXiv:1708.05393, 1703.08993, 1701.08240, 1701.02450,...

34. The Euclid survey: a new window on the last 10 billion years of cosmic history

Xavier Dupac (ESA)

13/09/2018, 11:10

Talk

Observational cosmology has made incredible progress in the last couple of decades, thanks to, notably, very precise observations of the Cosmic Microwave Background fluctuations, supernovae, galaxy clusters and large galaxy surveys. We now have good evidence that we live in an ever-expanding, accelerating Universe, spatially very close to flat, and the main cosmological parameters have been...

13. Generalized equations in the (S,0)+(0,S) representations of the Lorentz group

Valeriy Dvoeglazov (Universidad de Zacatecas)

13/09/2018, 11:30

Talk

I present several explicit examples of generalizations in relativistic quantum mechanics which may be used in astrophysics and cosmology.

First of all, I discuss the generalized spin-1/2 equations for neutrinos. They have been obtained by means of the Gersten-Sakurai method for derivations of arbitrary-spin relativistic equations. Possible physical consequences are discussed. Particularly, we...

6. Zerilli equation within a modified theory of General Relativity

Peter Hess (Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México)

13/09/2018, 11:50

Talk

For a modified theory of General Relativity, the pseudo-complex version, the stability of the Schwarzschild solution is investigated. The extended Zerilli equation is derived and the scattering of graviational waves investigated, which are the solutions of the Zerilli equation. Consequences for the ring-down frequency, after the fusion of two black holes, are studied.

136. Effects of delta-matter in neutron stars structure

Riccardo Belvedere (CBPF - Centro Brasileiro de Pesquisas Físicas, Brazil)

13/09/2018, 14:00

Talk

We investigate the effects due to the introduction of delta resonances in the neutron star matter. We compare and contrast the mass-radius diagram obtained for four different nuclear equations of state in the relativistic mean field theory. More precisely we vary the coupling constants for the delta-mesons interactions in the limits defined by the constraints on the relativistic mean field of...

44. Born-Infeld magnetars: larger than classical toroidal magnetic fields and implications for gravitational-wave astronomy

Jonas P. Pereira (Federal University of ABC & University of Southampton)

13/09/2018, 14:15

Talk

Magnetars are neutron stars presenting bursts and outbursts of X- and soft-gamma rays that can be understood with the presence of very large magnetic fields. In this setting, nonlinear electrodynamics should be taken into account for a more accurate description of such compact systems. We study that in the context of ideal magnetohydrodynamics and make a realization of our analysis to the case...

33. Gravitational waves from protoneutron stars and nuclear EOS

Hajime Sotani (National Astronomical Observatory of Japan)

13/09/2018, 14:30

Talk

We focus on spacetime oscillations, the so-called w-modes, of gravitational waves emitted from a protoneutron star in the postbounce phase of core-collapse supernovae. By adopting numerical results from recent relativistic three-dimensional supernova models, we find that the w1-mode frequency multiplied by the radius of the protoneutron star is expressed as a linear function with respect to...

92. Gravitational waves astrophysics - a review talk

Dorota Rosinska (University of Zielona Gora)

13/09/2018, 14:50

Talk

One of the most important prediction of Einstein's general theory of gravity is gravitational radiation. I will discuss the importance of the recent LIGO and Virgo direct detections of gravitational-waves. The observations of gravitational waves provide a different view on astrophysical processes hidden from electromagnetic astronomy and expand our knowledge of the Universe dramatically. I...

22. Oblique magnetic fields and the role of frame dragging

Vladimir Karas (Astronomical Institute, Czech Academy of Sciences)

13/09/2018, 15:30

Talk

Magnetic null points can develop near the ergosphere boundary of a rotating black hole by the combined effects of strong gravitational field and the frame-dragging mechanism. The electric component does not vanish in the magnetic null and an efficient process or particle acceleration can occur. The situation is relevant for low-accretion-rate nuclei of some galaxies which exhibit episodic...

12. Gravitational waves from core-collapse supernovae

Gennady Bisnovatyi-Kogan (Space Research Institute RAS)

13/09/2018, 15:50

Talk

Gravitational waves from core-collapse Supernovae.

G.S. Bisnovatyi-Kogan, S.G. Moiseenko

A mechanism of formation of gravitational waves in the universe is considered for the nonspherical collapse of matter. Nonspherical collapse results are presented for a uniform spheroid of dust, and a finite entropy spheroid. Numerical simulation results on core-collapse supernova explosion are presented...

137. IWARA2018 Review

Jorge Horvath (IAG-USP)

13/09/2018, 16:30

Talk

133. Baryon-quark phase transition in rotating hybrid stars

F. Köpp (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil)

Poster

In this work, we study the behavior of nuclear matter at high densities considering the hadronic and quark phases at zero temperature. We describe the hadron-meson phase using a phenomenological Lagrangian, which exhibits a parametrization, through mathematical constants, of the intensity of the several meson-nucleon couplings. We have included in the formalism the chemical equilibrium...

128. Chemical analysis of B stars in Orion

Maria Isela Zevallos Herencia (Universidad Nacional de Ingeniería, Lima, Perú)

Poster

In this work, a chemical analysis of a sample of B stars in the Orion Association is presented. This analysis consists in the calculation of the physical parameters: effective temperature ($T_{\rm eff}$) and surface gravity ($\log g$) by ionization equilibrium, and the determination of metal abundances of C, N, O, and Mg by a consistent analysis in non-LTE with TLUSTY. That is, the line...

127. Chiral phase transition in nonlocal NJL-like models under strong magnetic fields

Daniel Gomez Dumm (IFLP, CONICET - Dpto. de Física, Fac. de Cs. Exactas, Universidad Nacional de La Plata, Argentina)

Poster

We study the behavior of quark matter under an external magnetic field in the context of nonlocal chiral quark models, focusing on the features of the chiral restoration transition. It is seen that these models naturally lead to the inverse magnetic catalysis effect found in lattice QCD calculations.

79. CoLiTecVS – new tool for automated reduction of photometric observations

I. Kudzej (Vihorlat Observatory, Humenné, Slovakia,)

Poster

The capabilities of telescopes allow us to make the plotting of light curves a routine task. This one shifts the main attention of astronomer from the plotting to research. To achieve this goal, we developed a new tool for automated reduction of photometric observations, which includes the computational method for the brightness assessment of the investigated and comparison stars; brightness...

113. Compatibility of the dark matter condensation inside the neutron stars and their observed properties

Oleksii Ivanytskyi (Bogolyubov Institute for Theoretical Physics)

Poster

We study a compatibility of the dark matter condensation inside the neutron stars with the observational constraints on the properties of these astrophysical objects. Effects of the baryon-lepton matter are taken under control based on the well tested novel equation of state of nuclear matter, which is able to fulfil a rich collection of constraints from nuclear physics and heavy ion collision...

112. Condensation of tetraneutron in neutron stars

Oleksii Ivanytskyi (University of Salamanca)

Talk

Based on recent experimental and theoretical hints on possible formation of a resonant four-neutron system we study effects of appearance of such a cluster in neutron rich baryon matter inside NSs. For this purpose we employ a relativistic mean field approach which includes nucleons, Δ-baryons as well as light nuclear clusters. Our analysis demonstrates that tetraneutrons existing as the...

32. Constraining the nuclear EOS and neutron star models with QPOs from giant flares

Hajime Sotani (National Astronomical Observatory of Japan)

Poster

We examine crustal torsional oscillations, newly taking into account the effect of the pasta structure. We find from eigenmode analyses for various models of the equation of state of uniform nuclear matter that the fundamental frequencies of such oscillations are almost independent of the incompressibility of symmetric nuclear matter (K0), but strongly depend on the slope parameter of the...

89. Constraint interaction in dark sector with standard sirens

Riis Rhavia Bachega (Universidade de São Paulo)

Poster

The gravitational waves (GW) as standard siren directly determines the luminosity distance $d_L$ from progenitor source without assuming any cosmological model, of which the redshift $z$ can be obtained with the electromagnetic counterpart like GW events from coalescence binary neutron star (NS-NS) or neutron star/black hole (NS-BH) pair. In the near future, with the third generation GW...

100. Constraints on axionic dark matter in the 3-3-1 model

Ana Romero (Departamento de Raios Cósmicos e Cronologia, Instituto de Fisica Gleb Wataghin, UNICAMP)

Poster

Dark matter in the form of axions can be included in a model with $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$ symmetry with right handed neutrinos, where the strong CP problem can be solved. This version of the model has the appealing characteristic of giving the observed dark matter abundance measured by the Planck collaboration, for suitable values of the parameters in the model.
We studied the...

62. Constraints on the 3-3-1 model from dark matter searches

Carlos Enrique Alvarez-Salazar (Departamento de Raios Cósmicos e Cronologia, Instituto de Fisica Gleb Wataghin, UNICAMP)

Poster

We analyze the dark matter problem in a class of models with gauge symmetry $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$, taking into account the constraints coming from Planck observations of the dark matter relic density, direct detection searches with Xenon1T and indirect detection experiments.

110. Constraints on the number of X-ray pulsars in IC 10 from a deep XMM-Newton observation

Jun Yang (the University of Utah)

Poster

We report the most sensitive search yet for X-ray pulsars in the dwarf starburst galaxy IC 10, which is known to contain a population of young high mass X-ray binaries. A total of 207 point-like X-ray sources were detected in the direction of IC 10 by a 2012 XMM-Newton observation with a total exposure time of 134.5 ks. We searched for pulsations in 207 sources. Pulsation searches in faint...

88. Contribution of QCD condensates to the OPE of Green functions of chiral currents

Tomas Kadavy (Charles University)

Poster

In this contribution, basic properties of QCD condensates will be presented, together with theirs relation to the operator product expansion (OPE) and the two-point and three-point Green functions constructed of chiral currents. Next, we will discuss our newest results for contribution of the QCD condensates with dimension $D<6$ to the Green functions calculated within the framework of...

46. Determination of metallicity in Seyfert galaxies

Claudio Castro (UNIVAP - University of Vale do Paraíba)

Poster

During the last decades the work involving objects known as $Active~Galactic~Nuclei$ (AGNs) has been gaining more and more attention from several authors aiming at improving the already acquired knowledge. This knowledge provide us with the understanding of the physical processes occurring in AGNs as well as with a better mapping of the Universe. The initial proposal of the thesis project...

105. Eclipsing binaries stars in the Bulge Galactic direction with OGLE and MACHO data

Estefany Urday (Universidad Nacional de Ingenieria)

Poster

The OGLE catalogue contains position and photometry information in the I band of 200000 variable stars in the direction of Bulge Galactic. Another project, MACHO, scanned the same region obtaining information from millions of variable stars but in bands b and r. We chose the OGLE fields that were intercepted with the MACHO fields and we calculated the light curves of the stars contained in the...

134. Effective field theory for rotating neutron stars with genuine many-body forces

M. Razeira (Universidade Federal do PAMPA (UNIPAMPA), Caçapava do Sul, RS, Brazil)

Poster

The aim of our contribution is to shed some light on open questions facing the high-density nuclear many-body problem. We focus our attention on the conceptual issue of naturalness and its role in the baryon-meson coupling for nuclear matter at high densities. As a guideline for the strengths of the various couplings, the concept of naturalness has been adopted. In order to encourage possible...

141. Effective field theory with genuine many-body forces and tidal effect in neutron stars

B. Bodmann (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil), C.A.Z. Vasconcellos (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil), D. Hadjimichef (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil), F. Köpp (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil), G. Volkmer (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil), G.A. Degrazia (Universidade Federal de Santa Maria (UFSM), Santa Maria, RS, Brazil), M. Razeira (Universidade Federal do PAMPA (UNIPAMPA), Caçapava do Sul, RS, Brazil), M.V.T. Machado (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil)

Poster

In this contribution we combined our predictions for the tidal parameter with recent gravitational wave observation of merging system of binary neutron stars of the event GW170817 with quasi universal relations between the maximum mass of rotating and nonrotating neutron stars. Our results indicate that predictions of the tidal parameter represent an useful constraint of the EoS of neutron star matter.

131. EFT for rotating neutron stars with WIMPS and strong sigma(-) repulsion in the pc-GR theory

M. Razeira (Universidade Federal do PAMPA (UNIPAMPA), Caçapava do Sul, RS, Brazil)

Poster

On the scope of the pseudo-complex General Relativity (pc-GR), we investigate the role of many-body correlations in the maximum mass of rotating neutron stars with degrees of freedom of hyperons and weakly interacting massive dark matter particles (WIMPs) in their composition. In the baryon sector, we consider the effective relativistic QHD-model with parameterized couplings, which represents...

47. Electromagnetic counterpart of supermassive black hole binary mergers

Fabrícia Pereira (UNIVAP)

Poster

When a circumprimary gaseous disc is pushed into the primary supermassive black hole (SMBH) by the tidal force of the decaying secondary black hole, it can produce an increase in luminosity. In the case of a disc that lies in the same plane of the SMBHs binary, that luminosity exceeds the Eddington limit. However, in this work we show that misaligned binary-disc systems can present the mass...

115. Entropy evolution in CCDM cosmological models

Rodolfo Valentim (Unifesp - Diadema)

Poster

The second Law of Thermodynamics is an important approach to testing models and theories. If a model is not consistent with a constant or increasing entropy to achieve thermodynamic equilibrium must be discarded. Therefore, the study of Entropy suggests that it is possible to validate models or not. In this work, an approach is developed in light of the Second Law of Thermodynamics for Cold...

139. Exact solutions of a model for strange stars with interacting quarks

L. Rocha (IAG-USP, Brazil)

Poster

The search for the true ground state of dense matter remains open since thestrange matter hypothesis was proposed by E. Witten in 1984. In this hypothesis the strange matter is assumed to be composed of u, d and s quarks, having an energy per baryon lower than that of quark matter (only u and d), and even than of the nuclear matter. In this sense, neutron stars would actually be strange stars....

107. Exchange potential in KN scattering

Bruna Folador (UFRGS)

Poster

The Fock-Tani formalism is a first principle method to obtain effective interactions from microscopic Hamiltonians. Originally, derived for meson-meson or baryon-baryon scattering, we present the corresponding equations for meson-baryon scattering. Then we include the meson-quark coupling constant to the interaction potencial between quarks with gluon exchange. In particular, we shall obtain...

75. Follow-up of FAST pulsar discoveries

Marilyn Cruces (Max-Planck Institute for Radioastronomy)

Poster

Abstract:
Pulsars are fundamental tools for astronomy and physics. Every single new pulsar has the potential to provide an outstanding laboratory for a wide variety of physics, ranging from a better understanding of the stellar evolution to testing theories of gravity and placing limits on the equation-of-state. The most stable pulsars, who's precision approaches that of atomic clocks, are...

56. High energy processes in Wolf-Rayet stars

Stephen Skinner (Univ. of Colorado (Boulder))

Poster

Wolf-Rayet (WR) stars are massive stars that have evolved off the main-sequence and are undergoing advanced nuclear burning in their cores, rapidly approaching the end of their lives as supernovae. They are losing mass at very high rates and shocks associated with their metal-rich supersonic winds can produce strong X-ray emission, non-thermal (synchrotron) radio emission, and are potential...

43. Hyperonic neutron star matter in light of GW170817

William Spinella (Wentworth Institute of Technology)

Talk

Since 2013 the mass of pulsar PSR J0348+0432 ($M = 2.01\,M_{\odot}$) has provided a tight constraint on the neutron star equation of state. However, a number of different analyses of the recently detected binary neutron star merger (GW170817) point to a higher maximum neutron star mass of around $2.16\,M_{\odot}$. In addition, a recent study determined the mass of the millisecond pulsar PSR...

61. Impact of magnetic field on shape and velocities of compact objects

Aurora Perez Martinez (Instituto de Cibernetica Matematica y Fisica)

Talk

We study two macroscopic signals where the contribution of the magnetic field has an important role. The first one is related to kicks pulsar induced by neutrino emission from the core of neutron stars. The anisotropic neutrino emission produces a rocket effect that contributes to the star's kick velocity. We find that the computed values for the kick velocity lie within the range of the...

35. Investigating the photon and pomeron - induced dijets production at LHC

Eduardo Basso

Poster

We present a detailed comparison of the dijet production by photon–photon, photon–pomeron and pomeron–pomeron interactions in pp, pA and AA collisions at the LHC energy. The transverse momentum, pseudo-rapidity and angular dependencies of the cross sections are calculated at LHC energy using the Forward Physics Monte Carlo (FPMC), which allows one to obtain realistic predictions for the dijet...

39. Investigating the physics of ultrahigh energy neutrinos in neutrino telescope experiments

Magno Machado (IF-UFRGS)

Poster

We compute the corresponding number of events for PeV energy neutrinos for typical neutrino telescope experiments (Auger and IceCube experiments). We consider different parametrizations for the neutrino-nucleon cross section, including predictions from the geometric scaling phenomenon. The theoretical uncertainty for the number of events is investigated.

59. Mass dependent parameters of extensive air showers with anomalous longitudinal profiles

Vladimir Novotny (IPNP, Charles University, Prague)

Poster

We investigate possibilities to determine a mass of primary particle from anomalous longitudinal profiles of extensive air showers. Such profiles are predicted utilizing a Monte Carlo technique together with the contemporal high-energy interaction models. The depth of shower maximum, that is commonly used for the mass composition analyses, is inspected and its performace to discriminate...

24. Multi-particle fields as a method for hadron’s description

Dmytro Ptashynskyi (Odessa National Polytechnic University)

Poster

The development of multi-particle field method in the quarks scattering problem was considered. This method has been used to describe the differential cross section of elastic scattering by square of the transferred four-momentum. It is shown that the measurement of the interacting particles coordinates with simultaneity condition leads to impossible binding of probability amplitudes...

20. Neutrino structure functions predictions for high energy and high precision neutrino experiments

Mairon Melo Machado (Instituto Federal Farroupilha - Campus São Borja)

Poster

A QCD based analysis of the neutrino structure functions $xF2$, $xF3$ and $\Delta_{xF3}$, for charged current and neutral neutrino DIS is performed focusing on high energy and high precisions neutrino experiments. The investigation is done taking into account the color dipole formalism, considering a wide region of the kinematical variables Bjorken-$x$ and boson virtuality $Q^2$. We consider...

85. Non-geodesic corrections to mass-spin estimates for Galactic microquasars implied by QPO models

Andrea Kotrlova (Silesian University in Opava, Research Centre for Computational Physics and Data Processing)

Poster

We study frequencies of axisymmetric and non-axisymmetric epicyclic modes of accretion disc oscillations and explore the influence of pressure forces present in the disc. We discuss the implications for estimations of black hole spin in the three Galactic microquasars, GRS 1915+105, GRO J1655-40, and XTE J1550-564, that have been carried out based on several models of 3:2 high-frequency...

57. Nonthermal afterglow of GW170817: a more natural electron energy distribution leads to a new solution with radio flux in the low frequency synchrotron tail

Tomonori Totani (Univ. of Tokyo)

Poster

The nonthermal afterglow of the binary neutron star merger GW170817 has been modeled by synchrotron radiation of nonthermal electrons accelerated in the shock generated by ejecta or outflow from the merger. The previous afterglow modelings assumed that all the electrons in the shock are accelerated as a nonthermal population, and the minimum electron Lorentz factor gamma_m is the only...

55. On the Schwarzschild-Kottler black hole with cloud of strings

Geusa Marques (UFCG)

Poster

In the later 1970´s and early 1980´s, Letelier presented in a series of papers a formalism to treat gravity coupled to a cloud of strings, in the general relativity. Using this formalism, he obtained a generalization of the Schwarzschild solution in the sense that the resulting space-time is generated by a source constitued by a spherically symmetric body of mass M, surrounded by a...

98. Optimization of scintillators, applied to nuclear medicine and high energy physics

Alejandra Beatriz Altamirano Macetas (National University of Engineering), Carlos Javier Solano Salinas (National University of Engineering)

Poster

The project is focused on the optimization and characterization of inorganic scintillators. Scintillators are materials that emit light (flashes), when an energy particle deposits energy in its volume, it serves to collect light from the ionization process and has a wide range of applications that are find from the study of high-energy physics, astrophysics, nuclear physics, cosmic rays,...

84. Possible influence of neutron star magnetic field on the frequencies of twin-peak quasi-periodic oscillations

Eva Sramkova (Silesian University in Opava)

Poster

Motion of accreted gas approaching a neutron star (NS) in a NS low-mass X-ray binary (LMXB) system is determined by the relativistic scaling of orbital frequencies. The gas radiation dominates the NS LMXBs emissivity and accounts for most of the observed variability. As a likely consequence twin-peak quasi-periodic oscillations (QPOs) are observed in more than a dozen of sources. Motivated by...

138. Pseudo-complex general relativity and the slow-rotation approximation for neutron stars

G. Volkmer (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil)

Poster

Pseudo-complex General Relativity is an algebraic extension of the standard theory of gravitation that relies on pseudo-complex numbers in order to get new metric degrees of freedom. The pseudo-complex formalism has an extra contribution to the Einstein equations with a repulsive character that has been called dark energy. This dark energy is relevant only when intense gravitational fields...

28. Relativistic polytropic spheres with electric charge: Compact stars, compactness and mass bounds, and quasiblack hole configurations

José Arbañil (Universidad Privada del norte)

Poster

We study the static stellar equilibrium configurations of uncharged and charged spheres composed by a relativistic polytropic fluid, and compare with those of spheres composed by a non-relativistic polytropic fluid, the later case already being studied in a previous work [J. D. Arbañil, P. S. Lemos, V. T. Zanchin, Phys. Rev. D 88, 084023 (2013)]. For the two fluids under study, it is assumed...

83. Rotating compact stars using M.I.T bag model and QHD-I model

Fábio Köpp (UFRGS)

Poster

In this work we study hybrid composition stars using the M.I.T bag model and Walecka's linear model (QHD-I) for the core. For the region of lower density matter, i.e, the crust, we have used the Negele-Vautherin equation of state. When studying non- rotating stars, it is necessary to solve the conventional form of TOV's equations. However, for rotating stars, the metric must be modified to get...

135. Rotating dark matter compact star in the framework of the pseudo-complex general relativity

F. Köpp (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil)

Poster

In the theory of pseudo-complex General Relativity (pc-GR), the field equations have an extra term, associated to the nature of spacetime, of repulsive character, which is believed to halt the gravitational attractive collapse of matter distributions in the evolution process of compact stars. This additional term arises from micro-scale phenomena due to vacuum fluctuations, which simulate the...

53. Stellar structure models of magnetized white dwarfs

Omair Zubairi (Department of Sciences, Wentworth Institute of Technology)

Talk

Standard models of non-rotating compact stars assumes perfect spherical symmetry. However, due to high magnetic fields, these compact stellar objects can be deformed making them oblate or prolate spheroids with distinct equatorial and polar radii. Recent work on models of the global structure of highly magnetized neutron stars indicate the macroscopic stellar properties such as masses and...

132. Strangeness content of rotating neutron stars with hyperons and WIMPs degrees of freedom in the pseudo-complex general relativity

M.V.T. Machado (Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil)

Poster

A new constraint on the equation of state and matter composition of neutron stars has been provided by the measurement of the mass of PSR J0348+0432 (2.01 $M_\odot$). In this contribution, we investigate, in the domain of the pseudo-complex General Relativity (pc-GR) with baryons, mesons, electrons and weakly interacting massive dark matter particles (WIMPs) degrees of freedom, the role of the...

78. Thermodynamic stability of extremal black holes coupled to scalar fields

Paula Quezada Leon (PUCV)

Poster

We discuss thermodynamic stability of Riessner-Nördstrom (A)dS black hole in four dimensions, when it is coupled to the complex scalar field. Surprisingly, we show that it is unstable above or below some critical charge, if the scalar non-linearly couples to the black hole. This instability produces a second order phase transition near the critic point.

68. Three-dimensional simulations of rapidly rotating core-collapse supernovae

Tomoya Takiwaki (NAOJ)

Poster

We report results from a series of three-dimensional (3D) rotational core-collapse simulations for 11.2 and 27.0 $M_\odot$ stars employing neutrino transport scheme by the isotropic diffusion source approximation. By changing the initial strength of rotation systematically, we find a rotation-assisted explosion for the 27 $M_\odot$ progenitor, which fails in the absence of rotation. The unique...

102. Universal accelerations and the Tully-Fisher relation for spiral galaxies in conformal gravity

James O'Brien (Wentworth Institute of Technology)

Talk

In a recent paper McGaugh, Lelli, and Schombert showed that in an empirical plot of the observed centripetal accelerations in spiral galaxies against those predicted by the Newtonian gravity of the luminous matter in those galaxies the data points occupied a remarkably narrow band. While one could summarize the mean properties of the band by drawing a single mean curve through it, by fitting...

81. V348 Pav - A polar with an extremely low-mass white dwarf

Matheus Palhares (UNIVAP)

Poster

Cataclysmic Variables (CVs) are close binary systems composed of a white dwarf and a main sequence red star transferring mass to the compact object as it fills its Roche lobe. Polars are CVs where the white dwarf presents an intense magnetic field and material is transferred not by an accretion disc but is guided by the magnetic field lines to the white dwarf magnetic poles and have both...