PT Journal
AU Guendelman, EI
   Olmo, GJ
   Rubiera-Garcia, D
   Vasihoun, M
TI Nonsingular electrovacuum solutions with dynamically generated cosmological constant
SO Physics Letters B
JI Phys. Lett. B
PY 2013
BP 870
EP 875
VL 726
IS 4-5
DI 10.1016/j.physletb.2013.09.039
LA English
DE Modified gravity; Palatini formalism; Nonlinear electrodynamics; Dynamical cosmological constant; Nonsingular solutions; Wormholes
AB We consider static spherically symmetric configurations in a Palatini extension of General Relativity including R-2 and Ricci-squared terms, which is known to replace the central singularity by a wormhole in the electrovacuum case. We modify the matter sector of the theory by adding to the usual Maxwell term a nonlinear electromagnetic extension which is known to implement a confinement mechanism in flat space. One feature of the resulting theory is that the nonlinear electric field leads to a dynamically generated cosmological constant. We show that with this matter source the solutions of the model are asymptotically de Sitter and possess a wormhole topology. We discuss in some detail the conditions that guarantee the absence of singularities and of traversable wormholes.
ER