Black branes in asymptotically Lifshitz spacetime and viscosity/entropy ratios in Horndeski gravity

We investigate black brane solutions in asymptotically Lifshitz spacetime in 3+1-dimensional Horndeski gravity, which admit a critical exponent fixed at $z=1/2$. The cosmological constant depends on $z$ as $\Lambda=-(1+2z)/L^{2}$. We compute the shear viscosity in the 2+1-dimensional dual boundary field theory via holographic correspondence. We investigate the violation of the bound for viscosity to entropy density ratio of $\eta/s\geq1/(4\pi)$ at $z=1/2$.Comment: 7 pages, no figures, 1 table. Version published in EP

Braneworlds in Horndeski gravity

In this paper we address the issue of finding braneworld solutions in a five-dimensional Horndeski gravity and the mechanism of gravity localization into the brane via `almost massless modes' for suitable values of the Horndeski parameters. We compute the corrections to the Newtonian potential and discuss the limit where four-dimensional gravity is recovered.Comment: 14 pages, 6 figure