General Relativity and Quantum Cosmology
The Gravitational-Wave Transient Catalog (GWTC) is a collection of candidate gravitational-wave transient signals identified and characterized by the LIGO-Virgo-KAGRA Collaboration. Producing the contents of the GWTC from detector data…
The Gravitational-Wave Transient Catalog (GWTC) is a collection of short-duration (transient) gravitational-wave signals identified by the LIGO-Virgo-KAGRA Collaboration in gravitational-wave data produced by the eponymous detectors. The…
This study investigates the cosmological dynamics of an accelerating universe within the framework of teleparallel gravity using an exponential f(T) functional form. To obtain exact cosmological solutions, a hybrid scale factor is employed…
Gravitoelectromagnetism in the Weyl formalism is investigated through an analysis of the consequences of a restricted gauge symmetry acting on the tensor field $A_{\mu\nu}$. The propagator associated with the GEM field is explicitly derived…
LIGO, Virgo, KAGRA, and GEO form a network of gravitational-wave observatories. Data and analysis results from this network are made publicly available through the Gravitational Wave Open Science Center (GWOSC). This paper describes open…
We perform a first-principles canonical quantization of a massive vector field, often referred to as the Proca field, in a Schwarzschild spacetime background. While scalar, fermionic, and electromagnetic fields are well studied in this…
We ask whether two classical time-machine geometries, the Ori (2005) compact-vacuum-core metric and the Ahmed (2018) four-dimensional generalisation of Misner space, remain admissible exact solutions when the gravitational sector is…
The nonlinear stability of Minkowski spacetime has been one of the central achievements in the mathematical theory of general relativity and, more broadly, in the analysis of nonlinear geometric wave equations. Since the seminal work of…
We study entanglement harvested by Unruh DeWitt detectors following Rindler trajectories in compactified and superposed Minkowski spacetime. We consider different directions of acceleration (both parallel and antiparallel), separation…
In this paper, we systematically study three classes of three-dimensional Ba\~nados-Teitelboim-Zanelli (BTZ) black holes based on different gravitational frameworks and matter field structures: the Einstein-Maxwell BTZ, the F(R)-Maxwell…
We study circular motion of charged test particles on the equatorial slice of a Taub--NUT black hole with Manko--Ruiz parameter $C$, immersed in a weak external magnetic field introduced via Wald's prescription. Because the Taub--NUT metric…
We investigate black hole area quantization by imposing Landauer's principle on the discrete entropy change between consecutive area levels. The elementary transition is identified with the entropy cost of erasing one bit of information,…
In this work, we investigate the thermodynamic properties and quasinormal modes of a regular Dymnikova-Letelier black hole. Starting from the Einstein field equations sourced by an effective anisotropic fluid, we analyze the resulting…
We study rotating black holes in general relativity coupled to nonlinear electrodynamics (NED), focusing on an axisymmetric solution with deformation parameter g. On the spherical seed, weak-field lensing via the Gauss-Bonnet method and the…
We study a Simpson--Visser regularization of the four-dimensional Schwarzschild--anti--de\,Sitter (SV--AdS) black hole, treated as the bulk dual of a planar conformal field theory (CFT) on the AdS boundary. The bulk lapse…
Relying on the definition of asymptotic conformal Killing horizons, the generators of asymptotic conformal symmetries at future null infinity in Schwarzschild space-time are considered. The algebra they close is an extended version of the…
Cosmology where the effective dark energy crosses $w=-1$ can be realized in Horndeski gravity with shift symmetric terms plus a linear potential. We highlight the special role of the nearly conserved scalar charge. The theory is highly…
Heavy scalar fields ($m_\phi\gtrsim10^{-9}$ eV) in scalar-tensor gravity are expected to be hidden from neutron-star observations because their Compton wavelength is sub-stellar. We show that neutron stars can nevertheless scalarize by…
Black holes respond to infalling quantum matter fields by changing their entropy. Since such matter is quantum in nature, the entropy response should be sensitive to its quantum fluctuations. We show, within stochastic semiclassical…
We present an exact four-dimensional black string solution immersed in perfect fluid dark matter within an anti-de Sitter background. By solving the Einstein field equations for an anisotropic fluid, we obtain a metric function that…