Related papers: The Weak Gravity Conjecture, Overcharged Shells an…
Rich physics can be divined from charged black holes subjected to extremal conditions. When applied in conjunction with principles like Weak Cosmic Censorship, this naturally leads to constraints on the mass and charge of the black hole.…
Gravastars are considered as one of the prime exotic type compact objects which may be found at the end state of gravitational collapse of massive stars with a view to resolve the complexities that are pertinent in case of a black hole…
In this paper, we present the static charged solutions of quartic quasitopological gravity in the presence of a nonlinear electromagnetic field. Two branches of these solutions present black holes with one or two horizons or a naked…
"Wave gravity" refers to a quantum-mechanical gravity theory introduced in two previous papers [1,2]. Although based on the optics of de Broglie waves instead of curved space-time, it agrees with the standard tests of general relativity. As…
Modified gravity theories capable of genuine self-acceleration typically invoke a galileon scalar which mediates a long range force, but is screened by the Vainshtein mechanism on small scales. In such theories, non-relativistic stars carry…
The gravitational collapse of a thick cylindrical shell of dust matter is investigated. It is found that a spacetime singularity forms on the symmetry axis and that it is necessarily naked, i.e., observable in principle. We propose a…
This paper studies the influence of charge on a compact stellar structure also regarded as vacuum condensate star in the background of $f(\mathfrak{R},\mathcal{T}^{2})$ gravity. This object is considered the alternate of black hole whose…
Gauge/gravity duality is the conjecture that string theories have dual descriptions as gauge theories. Weakly-coupled gravity is dual to strongly-coupled gauge theories, ideal for lattice calculations. I will show precision lattice…
In this paper, we first introduce the Riesner-Nordstrom AdS (RN-AdS) black hole in presence of quintessence and cloud of strings. And then we use the Restrict Phase Space $(RPS)$ formalism in the corresponding black holes at the critical…
The weak gravity conjecture and the shear viscosity to entropy density bound place constraints on low energy effective field theories that may help to distinguish which theories can be UV completed. Recently, there have been suggestions of…
This paper investigates charged black holes within the framework of quintic quasi-topological gravity, focusing on their thermodynamics, conserved quantities, and stability. We construct numerical solutions and explore their thermodynamic…
Covariant $f(Q)$ gravity is a viable extension of General Relativity, however its strong-field predictions remain largely untested. Using the static, spherically symmetric black-hole solutions of the theory, we confront it with the most…
The swampland is the set of seemingly consistent low-energy effective field theories that cannot be consistently coupled to quantum gravity. In this review we cover some of the conjectural properties that effective theories should possess…
We study scenarios where a scalar field has a spatially varying vacuum expectation value such that the total field variation is super-Planckian. We focus on the case where the scalar field controls the coupling of a U(1) gauge field, which…
We consider the new version of the gedanken experiments proposed recently by Sorce and Wald to overcharge a static charged dilaton black hole. First of all, we derive the first-order and second-order perturbation inequalities in the…
With this note we want to point out that already in the early days of cosmology it was understood that negative pressure could eliminate gravitational singularities in a natural way e.g. E.B. Gliner, Sov. Phys. JETP 22(1966)378 and M.A.…
A Hamiltonian treatment of the gravitational collapse of thin shells is presented. The direct integration of the canonical constraints reproduces the standard shell dynamics for a number of known cases. The formalism is applied in detail to…
Supersymmetric String theories find occurrences of extremal Black Holes with gravitational mass M=Q where Q is the charge (G=c=1). Thus, for the chargeless cases, they predict M=0. We show that General Theory of Relativity, too, demands a…
It is well known that ($2+1$) dimensional charged BTZ (Banados, Teitelboim, Zanelli) black hole can be overcharged by a charged scalar field and a charged particle in contrast to their analogues in ($3+1$) and higher dimensions. In this…
Scalar-tensor theories of gravity that embrace conformal coupling to the scalar curvature are the focal point of cosmology on discussions of inflation and late-time accelerating universe. Although there exists a stringent nucleo-synthesis…