Advances in Astroparticle Physics and Cosmology (AAPCOS)

Session

Parallel

14 Oct 2015, 17:25

Meghnad Saha Auditorium (Saha Institute of Nuclear Physics)

92. Gravity mediated Preheating

Dr Debaprasad Maity (IIT Guwahati)

14/10/2015, 17:25

In this work we propose a mechanism of natural preheating of our universe induced by the inflaton field dependent effective mass term for the gravitational wave. For any single field inflationary model, the inflaton must go through the oscillatory phase after the end of inflation. As has recently been shown, if the gravitational fluctuation has inflaton dependent mass term, there will be a...

90. Thermodynamical Interpretation of Geometrical Variables Associated with Null Surfaces

Mr Sumanta Chakraborty (IUCAA)

14/10/2015, 17:25

The emergent gravity paradigm interprets gravitational field equations as describing the thermodynamic limit of the underlying statistical mechanics of microscopic degrees of freedom of the spacetime. The connection is established by attributing a heat density $Ts$ to the null surfaces where $T$ is the appropriate Davies-Unruh temperature and $s$ is the entropy density. The field equations...

86. Bounds on IDM from the electroweak vacuum metastability

Najimuddin Khan (Indian Institute of Technology Indore)

14/10/2015, 17:50

We add a $Z_2\mbox{-}odd$ complex scalar doublet to the Standard Model at TeV scale. The lightest neutral particle of the doublet is a viable dark matter candidate. We have shown various phase diagrams and point out the regions of absolute stability, meta-stability and instability for the electroweak vacuum and review the bounds on the model.

98. Inflationary predictions and moduli masses

Kumar Das (Saha Institute Of Nuclear Physics)

14/10/2015, 17:50

A generic feature of string/supergravity theories are moduli fields. The implication of moduli fields is a non-standard post-inflationary cosmological time-line when the energy density is dominated by cold moduli particles. This modification in the evolutionary hierarchy implies the preferred range in the number of e-folds between the horizon exit of relevant mode in CMB and the end of...

87. Consequences of Pilgrim Dark Energy in $f(T, T_G)$ cosmology

Dr Surajit Chattopadhyay (PCMT, Kolkata)

14/10/2015, 18:05

Pilgrim dark energy (PDE) model is studied in this paper and Hubble horizon has been used as an IR cutoff. The basic assumption of this model is that phantom acceleration prevents the formation of the BH. The said PDE is considered in a modified gravity $f(T, T_G)$, which has been constructed by Kofinas and Saridakis (2014) on the basis of $T$ (old quadratic torsion scalar) and $T_G$...

97. EVIDENCE FOR HIGH DENSITY EARLY UNIVERSE FROM ELEMENTARY PARTICLE PHYSICAL DATA

Prof. Girish T.E (Department of Physics ,UniversityCollege.Trivandrum 695034 India)

14/10/2015, 18:05

As supported by the hoop conjecture we show that elementary particles can transform in to micro black holes when its mass density reaches a critical value. These critical values are found to be proportional to the limiting relativistic mass of these particles given by the expression M=hc/2Gm where m is their rest mass. The mass densities of elementary particle black holes is found to mimic the...

99. The Space-time of Dark-matter

Dipanjan Dey (IIT Kanpur)

14/10/2015, 18:20

Dark-matter is a hypothetical matter which can't be seen but around 27% of our universe is made of it. Its distribution, evolution from early stage of our universe to present stage, its particle constituents all these are great unsolved mysteries of modern Cosmology and Astrophysics. In this talk I will introduce a special kind of space-time which is known as Bertrand Space-time (BST). I will...

89. Entropy Functional and Second Law in Curvature Squared Gravity

Dr Srijit Bhattacharjee (IIT Gandhinagar)

16/10/2015, 17:20

Nonrenormalizability of Einstein gravity has made us to believe that it is a low energy effective theory of a more fundamental theory, for example string theory. This low energy effective action generally contains an infinite number of higher curvature terms apart from the lowest order Einstein Hilbert term. It is thus important to survey the effects of such higher curvature terms on known...

100. Two neutrino double electron capture measurement using pixel detectors

Dr Joshy M. jose (Czech Technical University in Prague)

16/10/2015, 17:20

The TGV collaboration has been investigating the applicability of pixel detectors in the detection of two neutrino double electron capture (2$\nu$EC/EC) in $^{106}$Cd. Pixel detector gives spatial information along with energy of the particle, thus helps to identify and remove the background signals. The collaboration has proposed a Silicon Pixel Telescope (SPT) for the next generation...

93. Impact of sterile neutrinos on CP measurements at DUNE

Mehedi Masud (HRI)

16/10/2015, 17:40

Long-baseline neutrino experiments aim to measure the parameters responsible for neutrino oscillations. Now that θ13 has been conclusively shown to be non-zero and not too small, the focus has shifted to the measurement of the (Dirac) CP phase δCP that determines whether or not oscillating neutrinos violate CP. one of the main aim of the upcoming long baseline experiment DUNE is to measure...

91. HIgher spins as saviour of Quantum Universe

Dr Rudranil Basu (Indian Institute of Science Education and Research, Pune)

16/10/2015, 17:45

We consider toy example of 3 dimensional universe defined via definite thermal properties. This is modelled by Eucledian Einstein gravity with positive cosmological constant. In this background we couple higher spin interactions with pure gravity and calculate Euclidean path integral perturbatively. We confine ourselves to the static patch of the 3 dimensional de Sitter space. This geometry,...

94. The Direct Detection of Boosted Dark Matter at High Energies and PeV events at IceCube

Aritra Gupta (HRI, Allahabad)

16/10/2015, 17:55

We study the possibility of detecting dark matter directly via a small but energetic component that is allowed within present-day constraints. Drawing closely upon the fact that neutral current neutrino nucleon interactions are indistinguishable from DM-nucleon interactions at low energies, we extend this feature to high energies for a small, non-thermal but highly energetic population of DM...

95. Exploring Octant and CP violation at DUNE in presence of Reactor Experiments

Debajyoti Dutta (HRI, Allahabad)

16/10/2015, 18:10

Deep Underground Neutrino Experiment (DUNE) is an upcoming long baseline experiment at Fermilab, which aims to answer many fundamental questions both in particle physics and astrophysics. Neutrino physics is in the precision era. DUNE can answer questions regarding neutrino mass ordering, the octant of atmospheric mixing angle $\theta_{23}$ and most importantly it can probe CP violation in...

88. The k-essence scalar field in the context of Supernova Ia observations

Arka Moulik (RKMVU, Belur)

16/10/2015, 18:10

A k-essence scalar field model having (non canonical) Lagrangian of the form L=-V(\phi)F(X) where X=1/2g^{\mu\nu}\nabla_{\mu}\phi\nabla_{\nu}\phi with constant V(\phi) is shown to be consistent with luminosity distance-redshift data observed for type Ia Supernova. For constant V(\phi), F(X) satisfies a scaling relation which is used to set up a differential equation involving the Hubble...

96. Exploring Non Standard Physics in Long-Baseline Neutrino Oscillation Experiments

Sabya Sachi Chatterjee (Institute of Physics, Bhubaneswar)

16/10/2015, 18:25

After the recent discovery of large th_{13}, the focus has been shifted to address the remaining fundamental issues like neutrino mass ordering and CP-violation in leptonic sector. Future proposed Long-Baseline facilities like DUNE (1300 km baseline from FNAL to Homestake) and LBNO (2290 km baseline from CERN to Pyhasalmi) are well suited to address these issues at high confidence level. Not...