Double gravitational layer traversable wormholes in hybrid metric-Palatini gravity

In this work, we explore the existence of traversable wormhole solutions supported by double gravitational layer thin shells and satisfying null energy condition (NEC) throughout whole spacetime, in a quadratic-linear form generalized hybrid metric-Palatini gravity. We start showing that for particular action, junction conditions on continuity Ricci scalar $R$ Palatini $\mathcal{R}$ theory can be discarded without appearance undefined distribution terms field equations. As consequence, shell arises at separation hypersurface. then outline general method to find NEC throat provide an example. Finally, use previously derived match interior solution exterior vacuum asymptotic flat solution, thus obtaining full NEC. Unlike obtained scalar-tensor representation theory, which were scarce required fine-tuning, through are numerous exist wide variety metrics actions.