Thin-shells in F(R) theories (presentación oral, expositor)

ERNESTO F. EIROA; GRISELDA FIGUEROA AGUIRRE

La Falda, Córdoba

Conferencia; Grav15; 2015

FAMAF, Universidad de Córdoba, Argentina

The attempts to understand and explain the accelerated expansion of the Universe result in different theories, being the most standard ones those that use the concept of dark energy. Modifications of General Relativity have also been considered in order to describe this acceleration without employing exotic fluids, in particular the F(R) gravity models, where the Einstein-Hilbert Lagrangian is replaced by a function F(R) of the scalar curvature R. Within the framework of these theories, it is of interest the analysis of the behaviour of thin layers of matter by adopting the thin-shell formalism, which allows to match different solutions across a hypersurface. This formalism is characterized by certain requirements called junction conditions, which have been extended from General Relativity to F(R) theories in recent years. These conditions impose some requisites to the scalar curvature, namely F(R) theories generally present a continuous scalar curvature R, with the exception of quadratic F(R) theories in which R can be discontinuous as in the General Relativity case. Here we review the main features of the thin-shell formalism within the context of F(R) gravity.