Born–Infeld black holes in 4D Einstein–Gauss–Bonnet gravity

4D and 2D Evaporating Dilatonic Black Holes

The picture of S-wave scattering from a 4D extremal dilatonic black hole is examined. Classically, a small matter shock wave will form a non-extremal black hole. In the “throat region” the r − t geometry is exactly that of a collapsing 2D black hole. The 4D Hawking radiation (in this classical background) gives the 2D Hawking radiation exactly in the throat region. Inclusion of the back-reactio...

Black holes in three-dimensional topological gravity.

Vortices and black holes in dilatonic gravity

The extrapolation of the black hole ‘no-hair’ conjecture, initially proposed by Ruffini and Wheeler [1] and stating that a stationary black hole is uniquely determined by its mass, electromagnetic charge and angular momentum, to the stronger statement of ‘no dressing’ of the horizon, has been proven to be false [2], [3]. A common feature of such ‘counterexamples’ is that they involve nontrivial...

Astrophysical black holes in screened modified gravity

Chameleon, environmentally dependent dilaton, and symmetron gravity are three models of modified gravity in which the effects of the additional scalar degree of freedom are screened in dense environments. They have been extensively studied in laboratory, cosmological, and astrophysical contexts. In this paper, we present a preliminary investigation into whether additional constraints can be pro...

Non-singular Gravity without Black Holes Non-singular Gravity without Black Holes

Canada " What are the everywhere regular solutions of these field equations? " Abstract A non-singular static spherically symmetric solution of the nonsymmetric gravita-tional and electromagnetic theory (NGET) field equations is derived, which depends on the four parameters m, ℓ 2 , Q and s, where m is the mass, Q is the electric charge, ℓ 2 is the NGT charge of a body and s is a dimensionless ...