Degrees of freedom of f(T) gravity

MARÍA JOSÉ GUZMÁN MONSALVE

Afunalhue, Valdivia

Congreso; La parte y el todo - Tópicos avanzados en física de altas energías y gravitación; 2014

Pontificia Universidad Católica de Chile

We take a look at the issue of the degrees of freedom in f(R) and f(T) theories of gravity. Here R is the Ricci scalar and T refers to the scalar torsion invariant made up of the Weitzenböck connection in theories with teleparallelism. The case for f(R) is already well known, since the theory is equivalent to the Einstein-Hilbert action plus a scalar field. Depending if the theory is formulated in metric or Palatini formalism, the scalar field can or cannot be dynamical. However, due to its non-local Lorentz invariance, f(T) gravity has more extra degrees of freedom than f(R) gravity, and it is an open question its physical interpretation.