相关论文: String effect on the relative time delay in the Ke…
We calculate the time delay between different relativistic images formed by the gravitational lensing produced by the Gibbons-Maeda-Garfinkle-Horowitz-Stromiger (GMGHS) charged black hole of heterotic string theory. Modeling the…
We analyze gravitational lensing in the strong field limit for spherically symmetric string-inspired Euler-Heisenberg black holes, characterized by magnetic charge ($q$) and Einstein-Maxwell-dilaton coupling constants ($\alpha, \beta$) from…
Celebrating the centennial of its first experimental test, the theory of General Relativity (GR) has successfully and consistently passed all subsequent tests with flying colours. It is expected, however, that at certain scales new physics,…
We construct an effective four dimensional string-corrected black hole (4D SCBH) by rescaling the string coupling parameter in a $D$-dimensional Callan-Myers-Perry black hole. From the theoretical point of view, the most interesting…
We analytically study the optical appearance of an isotropically emitter orbiting near the horizon of a near-extremely rotating Kerr-Sen (KS) black hole which is an electrically charged black hole arising in heterotic string theory. We…
The quantum-corrected black hole model demonstrates significant potential in the study of gravitational lensing effects. By incorporating quantum effects, this model addresses the singularity problem in classical black holes. In this paper,…
Cosmic strings attached to rotating black holes extract its rotational energy, resulting in a mass loss and reduced spin. In this paper we discuss the proposed methods to detect these phenomena and present a novel methodology based on…
The Kerr-Sen black hole is a rotating charged black hole solution arising from heterotic string theory. In 4-dimensions effective theory the bosonic fields are: a $U(1)$ gauge boson, a Kalb-Ramond 3-form which is equivalent to a…
We consider the low-energy effective action of string theory at order $\alpha '$, including $R^2$-corrections to the Einstein-Hilbert gravitational action and non-trivial dilaton coupling. By means of a convenient field redefinition, we…
We introduce a new general-relativistic timing observable that measures the breaking of reflection symmetry in photon arrival times caused by black hole spin. Using backward ray tracing in the Kerr spacetime, we construct time-delay maps…
The perturbations of string-theoretic black holes are analyzed by generalizing the method of Chandrasekhar. Attention is focussed on the case of the recently considered charged string-theoretic black hole solutions as a representative…
In 4D general relativity, the angular momentum of a black hole is limited by the Kerr bound. We suggest that in string theory, this bound can be breached and compact black-hole-like objects can spin faster. Near such "superspinars," the…
We find a Kerr-like black hole solution-a rotating Bumblebee black hole (RBBH) with a Lorentz-violating parameter $\ell$ and examine the strong lensing by it. The parameter $\ell$ changes the event horizon radius and photon sphere,…
A rotating black hole threaded by an infinitely long cosmic string is studied in the framework of the Abelian Higgs model. We show that contrary to a common belief, in the presence of rotation the backreaction of the string does not induce…
We briefly review the present status of string theory from the viewpoint of its implications on the short-distance space-time structure and black hole physics. Special emphases are given on two closely related issues in recent developments…
The deflection of light in the gravitational field of a massive body can be analyzed through diverse theoretical approaches. The null geodesic approach is commonly employed to calculate light deflection within strong and weak field limits.…
Recent observational data from the Event Horizon Telescope (EHT) collaboration provide convincing realistic evidence for the existence of black hole rotation. From a phenomenological perspective, a recently proposed stable rotating regular…
Motivated by the first image of a black hole captured by the Event Horizon Telescope (EHT), there has been a surge of research using observations of black hole shadows to test theories of gravity. In this paper, we carry out a study related…
We consider modifications to general relativity by the non-local (classical and quantum) string effects for the case of a D-dimensional Scwarzschild black hole. The classical non-local effects do not alter the spacetime topology (the…
In a recent study [1], authors introduced a new class of exact space-times in Einstein's gravity, which are Kerr black holes immersed in an external uniform magnetic field that is oriented along the rotational axis. Motivated by this work,…