Traversable wormhole with double trace deformations via gravitational shear and sound channels

We investigate how nonlocal gravitational couplings from double trace deformation between two asymptotic boundaries of an AdS 5 black-brane can lead to the violation of the averaged null energy condition (ANEC). The first-order gravitational perturbations backreact with the background metric at second order, creating a wormhole opening in the context of the Gao-Jafferis-Wall traversable wormhole protocol. The wormhole becomes traversable in both the gravitational shear and sound channels within the hydrodynamic approximation. This shows that dynamical metric perturbations can facilitate information transfer in a purely gravitational setting, with the emergence of G N indicating the gravitational origin. For the shear channel, we consider three different coupling configurations, whereas for the sound channel, we vary both the speed of sound and the attenuation constant, as these parameters control the wormhole traversability. Furthermore, we obtain a late-time power-law factor in the ANEC using the fitting function and present a generalization that applies to both shear and sound channels. Due to its propagating nature, the sound channel exhibits late-time power-law remnants at low sound speed similar to the vector diffusive probes, but it prefers an exponential decay at higher sound speed similar to the scalar nondiffusive probes, as the power-law exponent weakened with increasing sound speed. For superluminal sound channels, the wormhole opens for an extremely brief duration at late insertion times, rendering it nontraversable.