A5049039171- Cosmology and Gravitation Theories
- Galaxies: Formation, Evolution, Phenomena
- Black Holes and Theoretical Physics
- Dark Matter and Cosmic Phenomena
- Advanced Thermodynamics and Statistical Mechanics
- Solar and Space Plasma Dynamics
- Gamma-ray bursts and supernovae
- Relativity and Gravitational Theory
- Astrophysics and Cosmic Phenomena
- Complex Systems and Time Series Analysis
- Astronomy and Astrophysical Research
- Stochastic processes and financial applications
- Statistical Mechanics and Entropy
- Geophysics and Gravity Measurements
- Stellar, planetary, and galactic studies
- Radio Astronomy Observations and Technology
- Astrophysical Phenomena and Observations
- Noncommutative and Quantum Gravity Theories
- Seismic Imaging and Inversion Techniques
- Pulsars and Gravitational Waves Research
- Earth Systems and Cosmic Evolution
- Quantum chaos and dynamical systems
- Computational Physics and Python Applications
- Gaussian Processes and Bayesian Inference
- Particle Detector Development and Performance
Valparaiso University
2012-2025
University of Valparaíso
2015-2024
Universidad Andrés Bello
2006-2008
Pontificia Universidad Católica de Valparaíso
2003-2004
Universidad de Santiago de Chile
1998-2002
The Cherenkov Telescope Array, CTA, will be the major global observatory for very high energy gamma-ray astronomy over next decade and beyond. scientific potential of CTA is extremely broad: from understanding role relativistic cosmic particles to search dark matter. an explorer extreme universe, probing environments immediate neighbourhood black holes voids on largest scales. Covering a huge range in photon 20 GeV 300 TeV, improve all aspects performance with respect current instruments....
We further investigate slowing down of acceleration the universe scenario for five parametrizations equation state dark energy using four sets supernovae data. In a maximal probability analysis we also use baryon acoustic oscillation and cosmic microwave background observations. found low redshift transition deceleration parameter appears, independently parametrization, data alone except Union 2.1 sample. This feature disappears once combine supernova with high conclude that rapid variation...
We present a novel cosmological framework that unifies matter creation dynamics with thermodynamic principles. Starting single-component fluid characterized by constant equation of state parameter, $\omega$, we introduce generalized second law thermodynamics considering the entropy associated cosmic horizon. Imposing an adiabatic expansion condition uniquely determines particle rate, $\Gamma$, feature unprecedented in previous models. This mechanism yields cosmology featuring phantom-like...
Abstract We present a novel cosmological framework that unifies matter creation dynamics with thermodynamic principles. Starting single-component fluid characterized by constant equation of state parameter, $$\omega $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>ω</mml:mi> </mml:math> , we introduce generalized second law thermodynamics considering the entropy associated cosmic horizon. Imposing an adiabatic expansion condition uniquely determines particle rate,...
I study the possibility of constructing an observationally viable scenario where both early inflation and recently detected accelerated expansion universe can be explained by using a single scalar field associated with tachyon. The reheating phase becomes crucial in enabling us to have consistent cosmology also get second period. A discussion exponential potential is presented.
In the context of thermodynamics we discuss way inevitable emerge an interaction between dark components, and in this way, provide a mechanism to understand limits LCDM model class models components. Using observational data have tested two particular explicit components reconstructed evolution temperatures for both We found that observations suggest exist with energy flowing from matter. The best fit also phantom equation state parameter energy. results having mind constraints imposed by...
We investigate the recent - low redshift expansion history of universe using most observational data. Using only data from 42 measurements $f_{gas}$ in clusters, we found that cosmic acceleration could have already peaked and are witnessing now its slowing down. This effect, previously by Shafieloo, Sahni Starobinsky 2010 supernova (at time Constitution SNIa sample) appears again an independent probe. also discuss result Union 2.1 set.
Considering a quadratic parametrization of the dark energy density, we explore signatures evolution using data from gas mass fraction in clusters, type Ia supernova, BAO and CMB. We find -- excluding CMB preference for $\rho_{de}(z)$ towards smaller values as redshift increases, result consistent with recent study DR11 by Delubac et al. (2015).
In this paper we constrain four alternative models to the late cosmic acceleration in Universe: Chevallier-Polarski-Linder (CPL), interacting dark energy (IDE), Ricci holographic (HDE), and modified polytropic Cardassian (MPC). Strong lensing (SL) images of background galaxies produced by galaxy cluster Abell $1689$ are used test these models. To perform analysis modify LENSTOOL lens modeling code. The value added probe is compared with other complementary probes: Type Ia supernovae (SNIa),...
We perform a study both statistical and theoretical for cosmological models of matter creation their ability to describe effective phantom dark energy. Such are beyond the $\Lambda$CDM model since resulting cosmic expansion is not adiabatic. In fact, we show that this approach exhibits transient phantom/quintessence scenarios at present time tends standard some stage evolution. discuss generalities thermodynamics properties type model; emphasize on behavior temperature associated matter,...
In this work we establish only at background dynamics level, the equivalence between Created Cold Dark Matter (CCDM) model and diverse dark energy (DE) models. We find that for a barotropic or linear equation of state (EoS) DE, $p=w \rho$, standard matter sector corresponding CCDM is described by same functional structure ratio particle production, $\Gamma$. For different EoS form $\Gamma$ term not longer maintained, however, in case polytropic given Chaplygin gas resulting can be written as...
In a recent paper, Liddle and Urena-Lopez suggested that to have unified model of inflation dark matter is imperative proper reheating process where part the inflaton field remains. this paper I propose possible. found incorporating effect plasma masses generated by products enables us stop process. A numerical estimated presented.
We study the orientation dependence of reconstructed deceleration parameter as a function redshift. use Union 2 and Loss datasets, by using well known preferred axis discussed in literature, finding best fit parameter. found that low redshift transition $q(z)$ is clearly absent one direction amazingly sharp opposite one. discuss possibility such behavior can be associated with large scale structures affecting data.
In this paper, we study the cosmic acceleration for five dynamical dark energy models whose equation of state varies with redshift. The cosmological parameters these are constrained by performing a Markov chain Monte Carlo (MCMC) analysis using mainly gas mass fraction, fgas, measurements in two samples galaxy clusters: one reported Allen et al., which consists 42 points spanning redshift range 0.05 < z 1.1, and other Hasselfield al. from Atacama Cosmology Telescope survey, 91 data |$0.118...
We explore the cosmological implications at effective level of matter creation effects in a dissipative fluid for FLRW geometry; we also perform statistical analysis this kind model. By considering an inhomogeneous Ansatz particle production rate obtain that created dark type can have quintessence scenario or future singularity known as little rip; dependence value constant parameter, $\eta$, which characterizes effects. The dimensionless age Universe is computed, showing number greater than...
In this work, we present a study of purely kinetic k-essence model, characterized basically by parameter $$\alpha $$ in presence bulk dissipative term, whose relationship between viscous pressure $$\Pi and energy density $$\rho the background follows polytropic type law, \propto \rho ^{\lambda +1/2}$$ , where $$\lambda principle, is without restrictions. Analytical solutions for field are found two specific cases: =1/2$$ =(1-\alpha )/2\alpha then show that these possess same functional form...