scholarly journals Thickenings and conformal gravity

1991 ◽  
Vol 139 (1) ◽  
pp. 1-43 ◽  
Author(s):  
Claude LeBrun
Keyword(s):  
Conformal Gravity

scholarly journals Spinning cosmic strings in conformal gravity

2020 ◽  
Vol 35 (05) ◽  
pp. 2050024
Author(s):  
Reinoud Jan slagter ◽  
Christopher Levi Duston
Keyword(s):  
Cosmic String ◽  
Energy Condition ◽  
Space Time ◽  
Special Choice ◽  
Mass Relation ◽  
Conformal Gravity ◽  
Field Equations ◽  
Closed Timelike Curves ◽  
The Core ◽  
Kerr Space

We investigate the space–time of a spinning cosmic string in conformal invariant gravity, where the interior consists of a gauged scalar field. We find exact solutions of the exterior of a stationary spinning cosmic string, where we write the metric as [Formula: see text], with [Formula: see text] a dilaton field which contains all the scale dependences. The “unphysical” metric [Formula: see text] is related to the [Formula: see text]-dimensional Kerr space–time. The equation for the angular momentum [Formula: see text] decouples, for the vacuum situation as well as for global strings, from the other field equations and delivers a kind of spin-mass relation. For the most realistic solution, [Formula: see text] falls off as [Formula: see text] and [Formula: see text] close to the core. The space–time is Ricci flat. The formation of closed timelike curves can be pushed to space infinity for suitable values of the parameters and the violation of the weak energy condition can be avoided. For the interior, a numerical solution is found. This solution can easily be matched at the boundary on the exterior exact solution by special choice of the parameters of the string. This example shows the power of conformal invariance to bridge the gap between general relativity and quantum field theory.

scholarly journals Conformal gravity with electrodynamics for fermion fields and their symmetry breaking mechanism

2014 ◽  
Vol 11 (03) ◽  
pp. 1450019 ◽  
Author(s):  
Luca Fabbri
Keyword(s):  
Scalar Fields ◽  
Specific Form ◽  
Conformal Gravity ◽  
Field Equations ◽  
Cosmological Constant Problem ◽  
Conformal Theory ◽  
Fermion Fields ◽  
Breaking Mechanism ◽  
Cosmological Constants ◽  
Dirac Spinors

In this paper, we consider an axial torsion to build metric-compatible connections in conformal gravity, with gauge potentials; the geometric background is filled with Dirac spinors: scalar fields with suitable potentials are added eventually. The system of field equations is worked out to have torsional effects converted into spinorial self-interactions: the massless spinors display self-interactions of a specific form that gives them the features they have in the non-conformal theory but with the additional character of renormalizability, and the mechanisms of generation of mass and cosmological constants become dynamical. As a final step we will address the cosmological constant problem and the coincidence issue.

scholarly journals Testing conformal gravity with the supermassive black hole in 1H0707-495

2018 ◽  
Vol 98 (2) ◽  
Author(s):  
Menglei Zhou ◽  
Zheng Cao ◽  
Askar Abdikamalov ◽  
Dimitry Ayzenberg ◽  
Cosimo Bambi ◽  
...  
Keyword(s):  
Black Hole ◽  
Conformal Gravity ◽  
Supermassive Black Hole

scholarly journals Gravitational lensing in conformal and emergent gravity

2019 ◽  
Vol 206 ◽  
pp. 07002
Author(s):  
Yen-Kheng Lim ◽  
Qing-hai Wang
Keyword(s):  
Exact Solution ◽  
General Relativity ◽  
Gravitational Lensing ◽  
Conformal Gravity ◽  
Null Geodesics ◽  
Linear Coefficient ◽  
Emergent Gravity ◽  
Bending Of Light

The gravitational bending of light in the framework of conformal gravity is considered where an exact solution for null geodesics in the Mannheim-Kazanas is obtained. The linear coefficient γ characteristic to conformal gravity is shown to contribute enhanced deflection compared to the angle predicted by General Relativity for small γ. We also briefly consider gravitational lensing in covariant emergent gravity.

scholarly journals FROM SPINOR GEOMETRY TO COMPLEX GENERAL RELATIVITY

2005 ◽  
Vol 02 (04) ◽  
pp. 675-731 ◽  
Author(s):  
GIAMPIERO ESPOSITO
Keyword(s):  
General Relativity ◽  
Minkowski Space ◽  
Dual Space ◽  
Conformal Gravity ◽  
Penrose Transform ◽  
Minkowski Space Time ◽  
Two Component ◽  
Spinor Geometry ◽  
Complex General Relativity ◽  
Component Spinor

An attempt is made of giving a self-contained introduction to holomorphic ideas in general relativity, following work over the last thirty years by several authors. The main topics are complex manifolds, two-component spinor calculus, conformal gravity, α-planes in Minkowski space-time, α-surfaces and twistor geometry, anti-self-dual space-times and Penrose transform, spin-3/2 potentials, heaven spaces and heavenly equations.

scholarly journals Spherical non-Abelian solutions in conformal gravity

2010 ◽  
Vol 81 (4) ◽  
Author(s):  
Y. Brihaye ◽  
Y. Verbin
Keyword(s):  
Conformal Gravity

scholarly journals Black holes in new massive conformal gravity

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
Yun Soo Myung ◽  
De-Cheng Zou
Keyword(s):  
Black Holes ◽  
Conformal Gravity

scholarly journals Magnetized Particle Motion around Black Holes in Conformal Gravity: Can Magnetic Interaction Mimic Spin of Black Holes?

Universe ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 44 ◽  
Author(s):  
Kamoliddin Haydarov ◽  
Ahmadjon Abdujabbarov ◽  
Javlon Rayimbaev ◽  
Bobomurat Ahmedov
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Black Hole ◽  
Particle Motion ◽  
Center Of Mass ◽  
Conformal Gravity ◽  
Mass Energy ◽  
Particle Collisions ◽  
Center Of Mass Energy ◽  
Sgr A

Magnetized particle motion around black holes in conformal gravity immersed in asymptotically uniform magnetic field has been studied. We have also analyzed the behavior of magnetic fields near the horizon of the black hole in conformal gravity and shown that with the increase of conformal parameters L and N the value of angular component of magnetic field at the stellar surface decreases. The maximum value of the effective potential corresponding to circular motion of the magnetized particle increases with the increase of conformal parameters. It is shown that in all cases of neutral, charged and magnetized particle collisions in the black hole environment the center-of-mass energy decreases with the increase of conformal parameters L and N. In the case of the magnetized and negatively charged particle collisions, the innermost collision point with the maximum center-of-mass energy comes closer to the central object due to the effects of the parameters of the conformal gravity. We have applied the results to the real astrophysical scenario when a pulsar treated as a magnetized particle is orbiting the super massive black hole (SMBH) Sgr A* in the center of our galaxy in order to obtain the estimation of magnetized compact object’s orbital parameter. The possible detection of pulsar in Sgr A* close environment can provide constraints on black hole parameters. Here we have shown that there is degeneracy between spin of SMBH and ambient magnetic field and consequently the interaction of magnetic field ∼ 10 2 Gauss with magnetic moment of magnetized neutron star can in principle mimic spin of Kerr black holes up to 0.6 .

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