25 citations · 52 across the 29 of their papers we have counts for
30 papers
Equilibrium \(\mathrm{H}_2^+/\mathrm{H}^-\) Abundance Ratios in MARCS Atmosphere Models
Aiganym Sarsembayeva, Hernando Quevedo
We investigate the equilibrium abundance ratio of the molecular hydrogen ion \(\mathrm{H}_2^+\) and the negative hydrogen ion \(\mathrm{H}^-\) in stellar atmospheres using compact…
Generalized Polytropic Regular Black Holes in Arbitrary Dimensions
Seyed Naseh Sajadi, Supakchai Ponglertsakul, Petarpa Boonserm +2
We investigate static, spherically symmetric regular black holes with anti-de Sitter (AdS) asymptotics in arbitrary spacetime dimensions. They are solutions of Einstein gravity, so…
Solving Einstein's Vacuum Equations with Physics-Informed Neural Networks: Boundary Conditions and Domain Decomposition
Elly Bayona, Hernando Quevedo
We investigate the application of Physics-Informed Neural Networks (PINNs) to the numerical solution of Einstein's vacuum field equations for static spacetimes. We first reproduce…
Geometric Universality and Thermodynamic Microstructure of Real Fluids in a Unified Entropic Framework
Carlos E. Romero-Figueroa, Jose Miguel Ladino, Sasha A. Zaldivar +1
We introduce a unified entropic framework for real fluids that encompasses the van der Waals, Berthelot, Redlich Kwong, and Peng Robinson equations of state within a common thermod…
Quasi-homogeneous geometrothermodynamics of a noncommutative Reissner-Nordstrom black hole
Alberto Maya, Hernando Quevedo
We present the thermodynamic properties of a noncommutative Reissner Nordstrom (NCRN) black hole (BH) modeled with Lorentzian distributions. The analysis is carried out using a Leg…
Quasi-Homogeneous Thermodynamics and Microscopic Structure of the Quantum-Corrected FLRW Universe
Carlos E. Romero-Figueroa, Hernando Quevedo
The analysis of phase transitions in cosmological spacetimes shows that their existence requires a time-dependent apparent horizon radius, which in turn implies an equation of stat…
Temperature definitions and phase transitions within non-minimal large and small inflationary potentials
Jesus Anaya-Galeana, Orlando Luongo, Hernando Quevedo
We explore and compare two distinct temperature definitions for scalar field inflation in the context of small- and large-field potentials. The first is based on a real gas, fluid-…
Thermodynamics of the FLRW apparent horizon in Einstein-Gauss-Bonnet gravity
Luis M. Sánchez, Hernando Quevedo
We analyze the thermodynamic properties of the apparent horizon of Friedmann-Lemaître-Roberson-Walker (FLRW) spacetimes in Einstein-Gauss-Bonnet gravity. We use the generalized def…
Constraining quadrupole deformations with relativistic effects
Daniya Utepova, Kuantay Boshkayev, Serzhan Momynov +4
We investigate two general relativistic effects - namely, the Shirokov and Shapiro effects - within the framework of the Zipoy-Voorhees spacetime (-metric), which generalizes th…
Non-extensive and quasi-homogeneous geometrothermodynamics
Hernando Quevedo, María N. Quevedo
We study the thermodynamic properties of black holes, taking into account the non-extensive character of their entropy at the thermodynamic and statistical level. To this end, we a…
Phase Transitions, Shadows, and Microstructure of Kerr-anti-de Sitter Black Holes from Geometrothermodynamics
Jose Miguel Ladino, Carlos E. Romero-Figueroa, Hernando Quevedo
Using the formalism of geometrothermodynamics, we investigate the phase-transition structure and microstructure of the Kerr-anti-de Sitter black hole and show the relationship with…
Geometric properties versus particle motion in the Fan-Wang spacetime
Gulnara Suliyeva, Kuantay Boshkayev, Talgar Konysbayev +7
In this work, we explore general relativistic effects and geometric properties of the Fan-Wang spacetime, one of the simplest regular solutions that can be obtained in nonlinear el…
Gravitational capture cross-section in Zipoy-Voorhees spacetimes
Serzhan Momynov, Kuantay Boshkayev, Hernando Quevedo +5
We consider geodesics of massive and massless test particles in the gravitational field of a static and axisymmetric compact object described by the quadrupolar metric (-metric)…
Event horizons under the effect of the Penrose process
Hernando Quevedo
We investigate how test particles absorbed by a black hole affect the properties of the event horizon. We consider particles that arrive from infinity with positive energy and cros…
Spherically symmetric collapse: Initial configurations
Elly Bayona, Hernando Quevedo, Miguel Alcubierre
The initial state of the spherical gravitational collapse in general relativity has been studied with different methods, especially by using {\it a priori} given equations of state…
Time is entropy: A geometric proof
Hernando Quevedo
We analyze the equilibrium space of an ideal gas using the formalism of geometrothermodynamics. We introduce the concept of thermodynamic geodesics to show that the equilibrium spa…
Smooth Functional Calculus and Spectral Theorem in Banach Spaces
Luis A. Cedeño-Pérez, Hernando Quevedo
The notion of projection families generalizes the classical notions of vector- and operator-valued measures. We show that projection families are general enough to extend the Spect…
A General Theory of Operator-Valued Measures
Luis A. Cedeño-Pérez, Hernando Quevedo
We construct a new kind of measures, called projection families, which generalize the classical notion of vector and operator-valued measures. The maximal class of reasonable funct…
Extended thermodynamics and critical behavior of generalized dilatonic Lifshitz black holes
Carlos E. Romero-Figueroa, Hernando Quevedo
We study a particular Einstein-Maxwell-Dilaton black hole configuration with cosmological constant, expressed in terms of the curvature radius, from the point of view of quasi-homo…
A thermodynamic model of inflation without inflaton field
Jesus Anaya-Galeana, Orlando Luongo, Hernando Quevedo
In the framework of geometrothermodynamics, we explore how to construct an inflationary cosmic fluid without requiring inflaton fields. To do so, we employ standard radiation and m…
Phase transitions, shadows, and microstructure of Reissner-Nordström-Anti-de-Sitter black holes from a geometrothermodynamic perspective
Jose M. Ladino, Carlos E. Romero-Figueroa, Hernando Quevedo
We study the thermodynamic properties of the Reissner-Nordström black hole with cosmological constant, expressed in terms of the curvature radius, by using the approach of shadow t…
Functional measures associated to operators
Luis A. Cedeño-Pérez, Hernando Quevedo
We show that every operator in has an associated measure on a space of functions and prove that it can be used to find solutions to abstract Cauchy problems, including part…
matching conditions for anisotropic fluids
Antonio C. Gutiérrez-Piñeres, Hernando Quevedo
The approach is an invariant formalism that utilizes the eigenvalues of the Riemann curvature tensor to match spacetimes across a specific matching surface. We apply this app…
On the single versus the repetitive Penrose process in a Kerr black hole
Remo Ruffini, Mikalai Prakapenia, Hernando Quevedo +1
Extracting the rotational energy from a Kerr black hole (BH) is one of the crucial topics in relativistic astrophysics. Here, we give special attention to the Penrose ballistic pro…