Related papers: Zero temperature black holes in semiclassical grav…
Building on general formulas obtained from the approximate renormalized effective action, the approximate stress-energy tensor of the quantized massive scalar field with arbitrary curvature coupling in the spacetime of charged black hole…
We compute the semiclassical current and stress-energy fluxes both at the event and Cauchy horizon of a near-extremal Reissner-Nordstr\"om black hole. We consider a minimally-coupled, massless, charged scalar field in the Unruh state,…
We study the solutions of the semiclassical Einstein equation in flat cosmological spacetimes driven by a massive conformally coupled scalar field. In particular, we show that it is possible to give initial conditions at finite time to get…
In this paper, we investigate the numerical solutions for spherically symmetric situations in Einstein cubic gravity. In addition to the previously found black hole solutions, we uncover a new class of solutions that lack horizons. Due to…
Iterative solutions to fourth-order gravity describing static and electrically charged black holes are constructed. Obtained solutions are parametrized by two integration constants which are related to the electric charge and the exact…
We present simple, analytic solutions to the Einstein-Maxwell equation, which describe an arbitrary number of charged black holes in a spacetime with positive cosmological constant $\Lambda$. In the limit $\Lambda=0$, these solutions reduce…
A new dyonic solution for black holes with spherically symmetric configurations in general relativity is obtained. We study black holes possessing electric and magnetic charges, and the source of the gravitational field is electromagnetic…
We obtain an exact spherically symmetric and magnetically charged black hole solution in 4D Einstein-Gauss-Bonnet gravity coupled with nonlinear electrodynamics with the Lagrangian ${\cal L}_{NED} = -{\cal F}/(1+\sqrt{2\mid\beta{\cal…
We perform the thermodynamic analysis of a charged Horndeski black hole (CHB) with mass $m$ and charge $q$ obtained from the Einstein-Horndeski-Maxwell theory. There are two solution branches: one is for the CHB and the other is for the…
We study two large classes of alternative theories, modifying the action through algebraic, quadratic curvature invariants coupled to scalar fields. We find one class that admits solutions that solve the vacuum Einstein equations and…
We study the possible existence of black holes in scalar-tensor theories of gravity in four dimensions. Their existence is verified for anomalous versions of these theories, with a negative kinetic term in the Lagrangian. The Hawking…
We investigate black hole solutions within a phenomenological approach to quantum gravity based on spacetime thermodynamics developed by Alonso-Serrano and Li\v{s}ka. The field equations are traceless, similarly to unimodular gravity, and…
We study 4-dimensional charged and static black holes in a generalized scalar-tensor gravity model, in which a shift symmetry for the scalar field exists. For vanishing scalar field the solution corresponds to the Reissner-Nordstr\"om (RN)…
We study Einstein's gravity with negative cosmological constant coupled to nonlinear electrodynamics proposed earlier. The metric and mass functions and corrections to the Reissner--Nordstr\"{o}m solution are obtained. Black hole solutions…
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…
We investigate the existence of Reissner-Nordstr\"om (RN) type black holes in f(R) gravity. Our emphasis is to derive, in the presence of electrostatic source, the necessary conditions which provide such static, spherically symmetric (SSS)…
We re-examine the black hole solutions in classical theories of dilaton gravity in two dimensions. We consider an arbitrary dilaton potential such that there are black hole solutions asymptotic at infinity to the nearly $\mathrm{AdS}_2$…
We construct spherically symmetric and static solutions in $F(R)$ gravity coupled with electromagnetic fields. The solutions include new types of black holes with electric and magnetic charges. We show that the higher-derivative terms make…
We investigate static and rotating charged spherically symmetric solutions in the framework of $f({\cal R})$ gravity, allowing additionally the electromagnetic sector to depart from linearity. Applying a convenient, dual description for the…
We construct models of Einstein and $f(R)$ gravity with two scalar fields, which admit analytical solutions describing time-varying dynamical black holes. Their thermodynamics is investigated in the adiabatic approximation. In addition to…