Kerr black-holes in modified teleparallel theories of gravity

CECILIA BEJARANO; RAFAEL FERRARO; MARÍA JOSÉ GUZMÁN MONSALVE

Buenos Aires

Congreso; II Argentinian-Brazilian Meeting on Gravitation, Astrophysics and Cosmology; 2014

In this work we analyze rotating black hole solutions in f(T) gravity. f(T)´s are theories of modified gravity coming from a deformation of the teleparallel equivalent of General Relativity (TEGR). They use torsion rather than curvature to describe gravity. This is because TEGR starts from the Weitzenbock connection, whose Riemann tensor is identically null. In teleparallelism, the dynamical variable is the tetrad or vierbein field, and the scalar Lagrangian T is quadratic in the torsion of the Weitzenbock connection. Differing from TEGR, f(T) theories lack the local invariance under Lorentz transformation of the tetrad. This feature is an obstacle to find solutions, even for highly symmetric geometries. In particular, the question about a suitable tetrad for the Kerr geometry is still open.