相关论文: Black holes in quartic-order beyond-generalized Pr…

In a subclass of generalized Proca theories where a cubic vector Galileon term breaks the $U(1)$ gauge invariance, it is known that there are static and spherically symmetric black hole (BH) solutions endowed with nonvanishing temporal and…

We study linear perturbations around a static and spherically symmetric black hole solution in spatially covariant gravity with just two tensorial degrees of freedom. In this theory, gravity modification is characterized by a single…

Although the entropy of black holes in any diffeomorphism invariant theory of gravity can be expressed as the Wald entropy, the issue of whether the entropy always obeys the second law of black hole thermodynamics remains open. Since the…

We consider the recently proposed non-relativistic Ho\v{r}ava-Lifshitz four-dimensional theory of gravity. We study a particular limit of the theory which admits flat Minkowski vacuum and we discuss thoroughly the quadratic fluctuations…

We construct quartic quasitopological gravity, a theory of gravity containing terms quartic in the curvature that yields second order differential equations in the spherically symmetric case. Up to a term proportional to the quartic term in…

Static spherically symmetric black holes are discussed in the framework of higher dimensional gravity with quadratic in curvature terms. Such terms naturally arise as a result of quantum corrections induced by quantum fields propagating in…

Bekenstein proved that in Einstein's gravity minimally coupled to one (or many) real, Abelian, Proca field, stationary black holes (BHs) cannot have Proca hair. Dropping Bekenstein's assumption that matter inherits spacetime symmetries, we…

Existence check of non-trivial, stationary axisymmetric black hole solutions in Brans-Dicke theory of gravity in different direction from those of Penrose, Thorne and Dykla, and Hawking is performed. Namely, working directly with the known…

We prove the constancy of surface gravity across a Killing horizon (not necessarily of bifurcate type) in arbitrary higher curvature theories of gravity coupled to Proca fields $-$ vector fields lacking $U(1)$ gauge invariance $-$ thus…

Generalized Proca theory supplements gravity with a massive vector field whose derivative self-interactions can support black holes carrying primary vector hair. In the asymptotically de Sitter branch considered here, the de Sitter scale is…

Black holes play an important role in linking microphysics with macrophysics, with those of the Planck mass ($M_P \sim10^{-5}$g) featuring in any theory of quantum gravity. In particular, the Compton-Schwarzschild correspondence posits a…

The gravitational-wave event GW170817, together with the electromagnetic counterpart, shows that the speed of tensor perturbations $c_T$ on the cosmological background is very close to that of light $c$ for the redshift $z<0.009$. In…

Exact, analytic, asymptotically flat rotating black-hole solutions are exceedingly rare, with only a handful of examples known. Using a Kerr-Schild ansatz, we derive a multitude of exact, analytic, asymptotically flat rotating black-hole…

The paper is based on the recently proposed 4-dimensional optical space theory and draws some of its consequences for gravitation. Starting with the discussion of central movement, the paper proceeds to establish the a metric compatible…

The gravitational wave event GW170817 together with its electromagnetic counterparts constrains the speed of gravity to be extremely close to that of light. We first show, on the example of an exact Schwarzschild-de Sitter solution of a…

We investigate how the speed of gravitational waves, $c_{GW}$, can be tested by upcoming black hole ringdown observations. We do so in the context of hairy black hole solutions, where the hair is associated with a new scalar degree of…

We address a dynamical, spherically symmetric background in beyond Horndeski theory and formulate a set of linear stability conditions for high energy perturbation modes above an arbitrary solution. In this general setting we derive speeds…

We study linear perturbations of the Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological model in the Regge-Wheeler formalism which is a standard framework to study perturbations of spherically-symmetric black holes. In particular, we…

Higher-order theories of gravity have received much attention from several areas including quantum gravity, string theory and cosmology. This paper proposes a higher-order gravity whose action includes all curvature scalar terms up to the…

We study linear perturbations on top of the static and spherically symmetric background of dyonic black hole solutions endowed with electric and magnetic charges, as well as a scalar hair, in the lowest-order $U(1)$ gauge-invariant…