Results 31 to 40 of about 13,435 (197)

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

European Physical Journal C: Particles and Fields, 2022
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 the Cold Dark Matter, Scalar Field Dark Matter, and the Universal ...
Reggie C. Pantig, Ali Övgün
doaj   +1 more source

From Homma's theorem to Pick's theorem [PDF]

, 2005
From Homma’s PL Gauss-Bonnet theorem applied on a PL-complex in a plane, many generalizations of Pick’s theorem on a lattice PL-figure are obtained in a unified geometric ...
Kurogi, Tetsunori, Yasukura, Osami
core   +2 more sources

Quasinormal modes, stability and shadows of a black hole in the 4D Einstein–Gauss–Bonnet gravity

European Physical Journal C: Particles and Fields, 2020
Recently a D-dimensional regularization approach leading to the non-trivial $$(3+1)$$ ( 3 + 1 ) -dimensional Einstein–Gauss–Bonnet (EGB) effective description of gravity was formulated which was claimed to bypass the Lovelock’s theorem and avoid ...
R. A. Konoplya, A. F. Zinhailo
doaj   +1 more source

Topological corrections and conformal backreaction in the Einstein Gauss–Bonnet/Weyl theories of gravity at $$D=4$$ D = 4

European Physical Journal C: Particles and Fields, 2022
We investigate the gravitational backreaction, generated by coupling a general conformal sector to external, classical gravity, as described by a conformal anomaly effective action.
Claudio Corianò, Matteo Maria Maglio, Dimosthenis Theofilopoulos   +2 more
doaj   +1 more source

Charged black holes in AdS spaces in 4D Einstein Gauss-Bonnet gravity

Physics Letters B, 2020
Recently a non-trivial 4-dimensional theory of gravity that claims to circumvent Lovelock's theorem and avoid Ostrogradsky instability was formulated in Glavan and Lin (2020) [1].
Pedro G.S. Fernandes
doaj   +1 more source

The Sub-Riemannian Limit of Curvatures for Curves and Surfaces and a Gauss-Bonnet Theorem in the Group of Rigid Motions of Minkowski Plane with General Left-Invariant Metric

Journal of Function Spaces, 2021
The group of rigid motions of the Minkowski plane with a general left-invariant metric is denoted by E1,1,gλ1,λ2, where λ1≥λ2>0. It provides a natural 2-parametric deformation family of the Riemannian homogeneous manifold Sol3=E1,1,g1,1 which is the ...
Jianyun Guan, Haiming Liu
doaj   +1 more source

Inner structure of Gauss-Bonnet-Chern Theorem and the Morse theory

, 2001
We define a new one form H^A based on the second fundamental tensor H^abA, the Gauss-Bonnet-Chern form can be novelly expressed with this one-form. Using the phi-mapping theory we find that the Gauss-Bonnet-Chern density can be expressed in terms of the ...
Duan, Yi-shi, Zhang, Peng-ming
core   +1 more source

On the Chern-Gauss-Bonnet Theorem and Conformally Twisted Spectral Triples for $C^*$-Dynamical Systems [PDF]

, 2016
The analog of the Chern-Gauss-Bonnet theorem is studied for a $C^*$-dynamical system consisting of a $C^*$-algebra $A$ equipped with an ergodic action of a compact Lie group $G$. The structure of the Lie algebra $\mathfrak{g}$ of $G$ is used to interpret
Fathizadeh, Farzad, Gabriel, Olivier
core   +4 more sources

Gauss–Bonnet–Chern theorem on moduli space [PDF]

Mathematische Annalen, 2013
Final version, Journal ref ...
Lu, Zhiqin, Douglas, Michael R.
openaire   +2 more sources

Deflection Angle of Photons through Dark Matter by Black Holes and Wormholes Using Gauss–Bonnet Theorem

Universe, 2019
In this research, we used the Gibbons–Werner method (Gauss–Bonnet theorem) on the optical geometry of a black hole and wormhole, extending the calculation of weak gravitational lensing within the Maxwell’s fish eye-like profile and dark-
Ali Övgün
doaj   +1 more source