Thin-shell wormholes in F(R) gravity (presentación oral, expositor)

GRISELDA FIGUEROA AGUIRRE; ERNESTO F. EIROA

Lisboa

Encuentro; Spanish-Portuguese Relativity Meeting EREP2016; 2016

Department of Physics of Instituto Superior Técnico and of Faculdade de Ciências, in the University of Lisbon

Different modifications of General Relativity have been proposed in order to understand the accelerated expansion of the Universe without invoking the presence of exotic fluids. Among them are the F(R) gravity theories, in which the Einstein-Hilbert Lagrangian is replaced by a function F(R) of the curvature scalar 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 the so called junction conditions, which have been extended from General Relativity to F(R) gravity in recent years. These conditions impose some requisites to the curvature scalar R, namely F(R) theories generally present a continuous R across the shell, 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 in F(R) gravity and we apply it to the construction of traversable wormholes with a throat at the joining shell. We consider the particular case of  spherically symmetric configurations, for which we present a stability analysis under radial perturbations.