Tideless traversable wormholes surrounded by cloud of strings in f(R) gravity

Abstract

We study the tideless traversable wormholes in the f(R) gravity metric formalism. First we consider three shape functions of wormholes and study their viabilities and structures. The connection between the f(R) gravity model and wormhole shape function has been studied and the dependency of the f(R) gravity model with the shape function is shown. We also obtain a wormhole solution in the f(R) gravity Starobinsky model surrounded by a cloud of strings. In this case, the wormhole shape function depends on both the Starobinsky model parameter and the cloud of strings parameter. The structure and height of the wormhole is highly affected by the cloud of strings parameter, while it is less sensitive to the Starobinsky model parameter. The energy conditions have been studied and we found the ranges of the null energy condition violation for all wormhole structures. The quasinormal modes from these wormhole structures for the scalar and Dirac perturbations are studied using higher order WKB approximation methods. The quasinormal modes for the toy shape functions depend highly on the model parameters. In case of the Starobinsky model's wormhole the quasinormal frequencies and the damping rate increase with an increase in the Starobinsky model parameter in scalar perturbation. Whereas in Dirac perturbation, with an increase in the Starobinsky model parameter the quasinormal frequencies decrease and the damping rate increases. The cloud of strings parameter also impacts prominently and differently the quasinormal modes from the wormhole in the Starobinsky model.

Quasinormal modes and optical properties of 4-D black holes in Einstein Power-Yang–Mills gravity

“…A notable trend within the table is the observed reduction in error associated with QNMs as the multipole moment l increases. This behaviour aligns with the characteristic limitations of the WKB approximation method, particularly evident when the overtone number n surpasses the multipole moment l. The diminishing error with increasing multipole moment is a distinctive feature of the WKB method, signifying its challenges in providing accurate results when overtone numbers exceed the corresponding multipole moment values [21,23,24,[59][60][61][62]. By keeping this fact in mind, in this investigation, we have considered n < l to calculate QNMs.…”

Quasinormal Modes and Greybody Factors of de Sitter Black Holes Surrounded by Quintessence in Rastall Gravity

“…Apart from Rastall gravity, quasinormal modes of black holes in different gravity theories have been investigated. [36][37][38][39][40][41][42][43][44] A comparison of such studies with this study can shed some more insights into the behavior of the quasinormal mode spectrum which can be utilized to differentiate between different gravity theories in the near future with observational results of quasinormal modes. Moreover, exploring the thermodynamics of the black hole in the Rastall gravity framework could clarify significant aspects of black hole physics like remnant mass and evaporation process.…”

New Wormhole Solutions in Quadratic f(Q)$f(\mathcal {Q})$‐Gravity Regime

“…[ 23 ] There have been numerous attempts to investigate the plausible models of the fictitious structure of wormholes. In the literature, there has been much discussion regarding the occurrence of wormhole solutions by including scalar fields, [ 24 ] quantum effects, [ 25 ] in a semiclassical gravity theory, [ 26 ] non‐singular spacetimes, [ 27 ] in the platform of brane‐world, [ 28,29 ] supported by Chaplygin gas with its modified and generalized forms, [ 30–33 ] in Gauss‐Bonnet theory, [ 34,35 ] rastall theory of gravity, [ 36 ] Lovelock gravity, [ 37–40 ] $$f(\mathcal {T})$$ gravity, [ 41,42 ] $$f(\mathcal {R, T})$$ gravity, [ 43,44 ] $$f(\mathcal {R})$$ gravity [ 45,46 ] etc.…”