Deriving weak deflection angle by black holes or wormholes usingGauss-Bonnet theorem

Y Kumaran, A Övgün - Turkish Journal of Physics, 2021 - journals.tubitak.gov.tr
In this review, various researches on finding the bending angle of light deflected by a
massive gravitating object which regard the Gauss-Bonnet theorem as the premise have …

Dark matter effect on the weak deflection angle by black holes at the center of Milky Way and M87 galaxies

RC Pantig, A Övgün - The European Physical Journal C, 2022 - Springer
In this paper, we investigated the effect of dark matter on the weak deflection angle by black
holes at the galactic center. We consider three known dark matter density profiles such as …

Shadow cast and Deflection angle of Kerr-Newman-Kasuya spacetime

A Övgün, I Sakallı, J Saavedra - Journal of Cosmology and …, 2018 - iopscience.iop.org
We study the shadow cast or silhouette generated by a Kerr-Newman-Kasuya (KNK)
spacetime (rotating dyon black hole). It is shown that in addition to the angular momentum of …

Gravitational lensing by rotating wormholes

K Jusufi, A Övgün - Physical Review D, 2018 - APS
In this paper the deflection angle of light by a rotating Teo wormhole spacetime is calculated
in the weak limit approximation. We mainly focus on the weak deflection angle by revealing …

Exact traversable wormhole solution in bumblebee gravity

A Övgün, K Jusufi, İ Sakallı - Physical Review D, 2019 - APS
In this study, we found a new traversable wormhole solution in the framework of a
bumblebee gravity model. With these types of models, the Lorentz symmetry violation arises …

Light deflection by Damour-Solodukhin wormholes and Gauss-Bonnet theorem

A Övgün - Physical Review D, 2018 - APS
In this paper, using the recent method proposed by Ono, Ishihara and Asada (OIA) who
extend the idea of Gibbons and Werner to the stationary and axisymmetric case, we apply …

Finite-distance gravitational deflection of massive particles by a Kerr-like black hole in the bumblebee gravity model

Z Li, A Övgün - Physical Review D, 2020 - APS
In this paper, we study the weak gravitational deflection angle of relativistic massive particles
by the Kerr-like black hole in the bumblebee gravity model. In particular, we focus on weak …

Weak lensing in a plasma medium and gravitational deflection of massive particles using the Gauss-Bonnet theorem. A unified treatment

G Crisnejo, E Gallo - Physical Review D, 2018 - APS
We apply the Gauss-Bonnet theorem to the study of light rays in a plasma medium in a static
and spherically symmetric gravitational field and also to the study of timelike geodesics …

Exact solution for a fermion–antifermion system with Cornell type nonminimal coupling in the topological defect-generated spacetime

A Guvendi, S Zare, H Hassanabadi - Physics of the Dark Universe, 2022 - Elsevier
We study the relativistic dynamics of a two-body system with nonminimal couplings in the
topological defect-generated 1+ 2-dimensional space–time by using a fully-covariant two …

Shadow and weak deflection angle of extended uncertainty principle black hole surrounded with dark matter

RC Pantig, KY Paul, ET Rodulfo, A Övgün - Annals of Physics, 2022 - Elsevier
In this paper, we discuss the possible effects of dark matter on a Schwarzschild black hole
with the correction of extended uncertainty principle (EUP), such as the parameter α and the …