Black holes in
f(Q) gravity
Black holes in
f(Q) gravityFabio D’Ambrosio,S. Fell,Lavinia Heisenberg,S. Kuhn
Abstract
We systematically study the eld equations of f(Q) gravity for spherically symmetric and stationary metricane spacetimes. Such spacetimes are described by a metric as well as a at and torsionless ane connection. In the Symmetric Teleparallel Equivalent of GR (STEGR), the connection is pure gauge and hence unphysical. However, in the non-linear extension f(Q), it is promoted to a dynamical eld which changes the physics. Starting from a general metric-ane geometry, we construct the most general static and spherically symmetric forms of the metric and the ane connection. We then use these symmetry reduced geometric objects to prove that the eld equations of f(Q) gravity admit GR solutions as well as beyondGR solutions, contrary to what has been claimed in the literature. We formulate precise criteria, under which conditions it is possible to obtain GR solutions and under which conditions it is possible to obtain beyond-GR solutions. We subsequently construct several perturbative corrections to the Schwarzschild solution for dierent choices of f(Q), which in particular include a hair stemming from the now dynamical ane connection. We also present an exact beyond-GR vacuum solution. Lastly, we apply this method of constructing spherically symmetric and stationary solutions to f(T) gravity, which reproduces similar solutions but without a dynamical connection.
