Abstract Recently, a static spherically symmetric black hole solution was found in gravity nonminimally coupled background Kalb-Ramond field. The Lorentz symmetry is spontaneously broken when the field has nonvanishing vacuum expectation value. In this work, we focus on quasinormal modes and greybody factor of hole. master equations for perturbed scalar field, electromagnetic gravitational can be written into Schrödinger equation. We use three methods to solve frequencies frequency domain....

A bstract Gravitational echoes can be used to probe the structure of spacetime. In this paper, we investigate gravitational in different braneworld models five-dimensional We derive perturbation equations these models, and obtain time-dependent evolution extra-dimensional radial components. Using a Gaussian wave packet as initial data, study time perturbation. By monitoring packet, are observed whether is generated from inside or outside braneworld. Furthermore, restrict parameters by...

Abstract In this paper, we study the scenario in which matter field is an electromagnetic nonminimally coupled to bumblebee vector field. We present exact charged spherically symmetric black hole solutions and slowly rotating gravity with without a cosmological constant. The static describe Reissner–Nordström-like Reissner–Nordström-(anti) de Sitter-like hole, while stationary axially Kerr–Newman-like Kerr–Newman–(anti) hole. utilize Hamilton–Jacobi formalism shadows of holes. Additionally,...

We explore the tensor perturbation of $f(T)$ brane embedded in an AdS$_5$ spacetime. With transverse-traceless condition, we get equation and show that stability this system can be ensured. In addition, take $ f(T)=T+\alpha T^2$ as example to analyse localization problem graviton zero mode. It is shown mode localized on brane.

The "complexity = action" duality states that the quantum complexity is equal to action of stationary AdS black holes within Wheeler-DeWitt patch at late time approximation. We compute growth rates neutral and charged in massive gravity neutral, Kerr-Newman $f(R)$ test this conjecture. Besides, we investigate effects graviton terms, higher derivative terms topology hole horizon on rate.

Abstract Seeking singularity free solutions are important for further understanding black holes in quantum level. Recently, a five-dimensional hole/topological star was constructed (Bah and Heidmann Phys Rev Lett 126:151101, 2021). Through the Kaluza–Klein reduction, an effective four-dimensional static spherically symmetric charged hole with scalar hair can be obtained. In this paper, we study shadow of terms four kinds observers, i.e., surrounding freely falling escaping observers...

ABSTRACT Gravitational-wave (GW) astronomy, together with precise pulsar timing and long baseline interferometry, is changing our ability to perform tests of fundamental physics astrophysical observations. Some these are based on electromagnetic (EM) probes or electrically charged bodies, assume an empty Universe. However, the cosmos filled plasma, a dilute medium which prevents propagation low-frequency, small-amplitude EM waves. We show that plasma hinders some strong-field gravity tests,...

We study the axial gravitational quasinormal modes of a self-dual black hole in loop quantum gravity. Considering perturbation background spacetime, we obtain Schr\"odinger-like master equation. Then calculate frequencies with Wentzel-Kramers-Brillouin approximation and asymptotic iteration method. also investigate numerical evolution an initial wave packet on spacetime. find correction parameter $P$ positively affects absolute values both real imaginary parts frequencies. derive relation...

Abstract In this paper, we investigate the optical properties of a charged black hole with scalar hair (CSH) within context four-dimensional Einstein–Maxwell–Dilaton gravity. To achieve this, consider three distinct toy models thin accretion disks. The presence dilaton coupling allows us to express both solutions CSH and Reissner–Nordström (RN) in terms their mass ( M ) charge Q ). Our findings reveal differences effective potentials $$V_{eff}$$ <mml:math...

A bstract In this work, we study the gravitational quasinormal modes of thick brane in Rastall gravity. Using asymptotic iteration and direct integration methods, solve frequencies brane. We also obtained waveforms these through numerical evolution. The results indicate that although lacks a bound zero mode, when parameter λ ≳ 0, long-lived mode appears. This may restore four-dimensional effective Newtonian potential on large scale. provide new perspective for localization gravity branes,...

In this work, we investigate the gravitational quasinormal modes (QNMs) and resonances of a thick brane model. We use asymptotic iteration shooting methods to obtain frequencies (QNFs) brane. On other hand, their evolution numerically. The results show that oscillations equal (up numerical error) real parts QNFs, while damping rates imaginary QNFs. QNMs resonances---both them can be regarded as characteristic brane---are closely related with each other. addition, lifetime these could very...

In this paper we investigate the innermost stable circular orbit (ISCO) for a classical spinning test particle in background of Kerr-Newman black hole. It is shown that related to spin particle. The motion will be superluminal if its too large. We give an additional condition by considering constraint ISCO hole backgrounds. obtain numerically relations between and properties holes found radius smaller than non-spinning

We apply the mimetic f(T) theory into thick brane model. take Lagrange multiplier formulation of action and get corresponding field equations motion. find solutions for different kinds f(T). Besides, we investigate stability by considering tensor perturbations vielbein. Localization problem is also studied it shown that four-dimensional gravity can be recovered all solutions. The effects torsion show polynomial form f(T), zero mode has a split compared with f(T)=T, but situations exponential...

In this work, we investigate the quasinormal modes of a thick brane system. Considering transverse-traceless tensor perturbation metric, obtain Schr\"odinger-like equation Kaluza-Klein perturbation. Then use Wentzel-Kramers-Brillouin approximation and asymptotic iteration method to solve equation. We also study numeric evolution an initial wave packet against brane. The results show that there is set discrete in model. These appear as decaying massive gravitons for observer. They are...

The Born-Infeld $f(T)$ theory is reduced from the determinantal gravity in Weitzenb\"ock spacetime. We investigate a braneworld scenario this and obtain an analytic domain wall solution by utilizing first-order formalism. model stable against linear tensor perturbation. It shown that massless graviton localized on brane, but continuous massive gravitons are non-localized will generate tiny correction with behavior of ${1}/{(k r)^{3}}$ to Newtonian potential. four-dimensional teleparallel...

In this paper, we study the structure and gravitational resonances of thick branes generated by a mimetic scalar field in $f(R)$ gravity. We obtain several typical brane solutions for $f(R)=R+\alpha R^2$. To their stability, analyze tensor perturbation metric. It is shown that any model with $df/dR>0$ stable graviton zero mode can be localized on each solution, which indicates four-dimensional Newtonian gravity restored. The effect parameter $\alpha$ studied. As splits into multi sub-branes,...

In order to localize fermions on branes with codimension 1, one usually introduces the Yukawa coupling between and background scalar fields or recently proposed derivative fermion-scalar [Phys. Rev. D 89, 086001 (2014)]. this paper, we explore a spinor field $\mathrm{\ensuremath{\Psi}}$ curvature of spacetime $R$, $\ensuremath{\eta}\mathrm{\ensuremath{\Psi}}{\mathrm{\ensuremath{\Gamma}}}^{M}{\ensuremath{\partial}}_{M}F(R){\ensuremath{\gamma}}^{5}\overline{\mathrm{\ensuremath{\Psi}}}$ $F(R)$...

In this paper, we investigate the braneworld scenario in $f(T)$ gravity with a $K$-field as background field. We consider various different specific forms of and $K$-field, find general way to construct model. Based on our solutions, split branes is investigated. Besides, stability studied by investigating tensor perturbation vielbein.

Abstract In this work, we investigate the gravitational resonances in various f ( T )-brane models with warp factor $$\text {e}^{A(y)}=\tanh \big (k(y+b)\big )-\tanh (k(y-b)\big )$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mtext>e</mml:mtext> <mml:mi>A</mml:mi> <mml:mo>(</mml:mo> <mml:mi>y</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:msup> <mml:mo>=</mml:mo> <mml:mo>tanh</mml:mo> <mml:mi>k</mml:mi> <mml:mo>+</mml:mo> <mml:mi>b</mml:mi>...

Abstract In this work, we investigate the numerical evolution of massive Kaluza–Klein (KK) modes a scalar field in thick brane. We derive Klein–Gordon equation five-dimensional spacetime, and obtain Schrödinger-like equation. With resonances KK as initial data, is evolved with maximally dissipative boundary condition. The results show that there are resonant particles long life on brane, which indicates these might be regarded candidate for dark matter.

From the quantum point of view, singularity should not exist. Recently, Bah and Heidmann constructed a five-dimensional free topology star/black hole [Phys. Rev. Lett. 126, 151101 (2021)]. By integrating extra dimension, four-dimensional static spherical black with magnetic charge scalar hair can be obtained. In this paper, we study quasinormal modes (QNMs) field gravitational on background charged hair. The odd parity perturbations couples even perturbations. Two coupled second-order...

It is known that there are two mechanisms for localizing a bulk fermion on brane: one the well-known Yukawa coupling, and other new coupling proposed in [Phys. Rev. D 89, 086001 (2014)]. In this paper, we investigate localization resonance spectrum of same branes with mechanisms. found both can result volcano-like effective potential Kaluza-Klein modes. The left-chiral zero mode be localized brane, exist some discrete massive-fermion modes quasilocalized (also called resonances). number...