Constructing black holes in Einstein–Maxwell-scalar theory

Scalar Black Holes

A class of exact regular spherically symmetric solutions to the Einstein equation obeying Dymnikova’s definition T 1 1 = T 0 0 of vacuumlike state is considered. These solutions, that may be interpreted as black holes, are not only singularity free, but also do not set us thinking about the loss of information under gravitational collapse. However, according to the singularity theorems, the geo...

Cold Black Holes in Scalar-tensor Theories

We study the possible existence of black holes in scalar-tensor theories of gravity in four dimensions. Their existence is verified for anomalous versions of these theories, with a negative kinetic term in the Lagrangian. The Hawking temperature TH of these holes is zero, while the horizon area is (in most cases) infinite. It is shown that an infinite value of TH can occur only at a curvature s...

Static black holes in scalar tensor gravity

We study static black hole solutions in scalar tensor gravity. We present exact solutions in hiperextended models with a quadratic scalar potential. On leave from: Departamento de F́ısica da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto, Portugal

Caged Black Holes: Black Holes in Compactified Spacetimes I – Theory

In backgrounds with compact dimensions there may exist several phases for black objects including the black-hole and the black-string, and the phase transition between them raises puzzles and touches fundamental issues such as topology change, uniqueness and cosmic censorship. No analytic solution is known for the black hole, and moreover, one can expect approximate solutions only for very smal...

Charged black holes with scalar hair.