Speaker
José Beltrán-Jimenez
(U. Salamanca)
Description
In this talk I will review some of the pathologies that typically arise in modified gravity theories. I will adopt a geometrical perspective to modifications of GR taking the Geometrical Trinity of Gravity as starting point and will mainly focus on teleparallel theories. In particular, I will discuss the unavoidable presence of ghosts in the so-called f(Q) theories. To end with a positive message, a class of ghost-free theories in the symmetric teleparallel framework that is based on a TDiff symmetry will be introduced.
