Conveners
Parallel session B
- Luis Otiniano
Parallel session B
- Christian Mejía Guamán (Universidad de Cuenca)
Parallel session B
- Oscar Lasso (Universidad de Las Américas)
Parallel session B
- JORGE ALFARO (Pontificia Universidad Católica de Chile)
Parallel session B
- Carlos Antonio Marín Vásconez (Universidad San Francisco de Quito)
Description
Shorter talks for accepted abstracts
We show that convection cells in the stellar photosphere generate plasma waves by a process akin to sonic booms and Zeldovich superradiance. Our theoretical approach is based on the Markovian master equation for each mode of the quantum field corresponding to such waves. For the Sun, this mechanism is most efficient in quiet regions with small magnetic fields. Energy is mostly carried by...
I will consider some examples of Dark Matter (DM) models where the DM can be described by a collection of oscillating (scalar, vector or tensor) waves. I will present the basic phenomenology and recent results on some observational probes that are useful to probe models of ultra-light DM.
Low-cost imaging technology is widely used for particle detection. In this work, we test the performance of an Omnivision 5 Mp CMOS sensor for measuring radioactive sources (Sr90 and Cs137). Our experimental setup includes a light-tight box, a lift table and a Raspberry Pi 3 for data taking using fixed camera settings. To reduce the background we apply a correlated double sampling method for...
In the last two decades, cosmic ray muon-based imaging, or muongraphy, has undergone tremendous development and has found applications in different fields that require penetrating probes in large or high-density volumes. The unique characteristics of this technique make it particularly important for applications including nuclear non-proliferation, spent nuclear reactor fuel monitoring, cargo...
Cosmic rays are high-energy subatomic particles that reach Earth from outer space. Interacting with the atmosphere forms Extensive Air Showers of particles (EAS), also called secondary cosmic rays, which can be detected with different techniques, among them are Water Cerenkov Detectors (WCD) such as those developed by the LAGO Collaboration.
The hadronic component of EAS contains neutrons...
Whenever new states of matter are discovered, or a new energy window is opened, there is need and interest to look for new physics. Phases of matter described by topological order have attracted such attention. On the one hand they seem promising for applications such as quantum computation or spintronics and on the other they may shed some lights on axion physics, or on possible...
In the context of String theory, the Swampland is the set of consistent field theories that cannot be completed into quantum gravity in the ultraviolet regime. Thus, the string theories lead to huge amount of effective-low energy theories, and the swampland is the collection of effective theories that cannot come from string theory. Therefore, it is very useful to find constraints over the...
In the era of information technology higher education and resarch is rapidly globalizing, links scientists institutions, society and industry are strengthened and discussions about adopting Open Science principles is on the table. Virtual Learning Comunities (VRLC) play a fundamental role in modernization and internationalization of higher education. VRLCs create new opportunities:...
Linearized gravity in the Very Special Relativity (VSR) framework is considered. We prove that this theory allows for a non-zero graviton mass $m_g$ without breaking gauge invariance nor modifying the relativistic dispersion relation. We find the analytic solution for the new equations of motion in our gauge choice, verifying as expected the existence of only two physical degrees of freedom....
We have studied how local density perturbations could reconcile the Hubble tension. We reproduced a local void through a perturbed FLRW metric with a potential $\Phi$ which depends on both time and space. This method allowed us to obtain a perturbed luminosity distance, which is compared with both local and cosmological data. We got a region of local parameters, $q_0^\text{Lo}$ and...
We implemented in the popular Boltzmann solver CLASS a holographic dark energy (HDE) model with two infrared (IR) cut-offs: the Ricci scalar curvature (RDE) and its more general version the Granda-Oliveros (GO). For the background, we show that the HDE density using the GO cut-off can exhibit radiation, matter, or DE behavior depending on the component that dominates the energy...
We present the Hamiltonian formulation of the gravitational sector of the Standard-Model-Extension, which introduces the breaking of diffeomorphism symmetry through explicit background fields. The modified gravity theory is shown to require an extension of the Gibbons-Hawking-York boundary term and to produce Hamilton-Jacobi equations of motion that are equivalent to the projected modified...
This talk shows a general procedure to construct hairy rotating black holes by deforming a spherically symmetric solution following the Gravitational Decoupling approach. We demonstrate that, in comparison with the well-known Newman-Janis algorithm (with and without complexification), the application of our protocol is straightforward. We provide a particular example of a solution that reduces...
One of the most used strategies to model compact objects is considering equations of state that outline the most important physical processes among their thermodynamic variables. Perturbation analysis of its physical variables allows discerning between stable and unstable configurations, providing models that could describe observed objects.
In this work, we studied the physical...
Ultracompact stars or “gravastars” were modeled firstly by Mazur and Mottola (MM) by the use of the Schwarzschild interior solution in a special case. Recently, the MM model has been extended to anisotropic domains by the Gravitational Decoupling (GD) through the Minimal Geometric Deformation (MGD) approach. In contrast to the original solution, the resulting configuration can be matched...
In this work we construct traversable wormholes
geometries in the framework of the complexity factor. We
provide the redshift function of a Casimir traversable worm-
hole which, in combination with a non-vanishing complex-
ity factor, leads to a traversable wormhole with a minimum
amount of exotic matter. The shape function and the embed-
ding diagram are shown and discussed. The tidal...
We consider gravitational collapse of a fluid sphere with torsion generated by spin, which forms a black hole.
We use the Tolman metric and the Einstein-Cartan field equations with a relativistic spin fluid as a source.
We show that gravitational repulsion of torsion prevents a singularity, replacing it with a nonsingular bounce.
Quantum particle creation during contraction prevents shear...
Ideas originally developed for axion dark matter can be adopted to search for high-frequency gravitational waves. To illustrate this, I will discuss the Gertsenshtein effect, or the inter-conversion of gravitational waves into electromagnetic waves in the presence of external magnetic (or electric) fields. Exploiting the analogy with axions I will show that axion haloscopes based on...
The observation of GW170817 binary neutron star (BNS) merger event has imposed strong bounds on the speed of gravitational waves (GWs) locally, inferring that the speed of GWs propagation is equal to the speed of light. Current GW detectors in operation will not be able to observe BNS merger to long cosmological distance, where possible cosmological corrections on the cosmic expansion history...
The study of Emergent Universe models (EU) is based on the assumption that the universe emerges from a past eternal Einstein static state (ES) towards an inflationary phase. The EU is an attractive scenario since it avoids the initial singularity and provides a smooth transition towards an inflationary period.
In this context, it has been pointed out by Mithani-Vilenkin that certain...
