Search Talks

It has been shown by Hertog and Horowitz that certain AdS boundary conditions allow non-singular initial conditions to evolve into a Big Crunch. To study this kind of cosmological singularities, one can use the dual quantum field theory, where the singularity is manifested by the presence of a multi-trace potential unbounded below. Recently, Craps, Hertog and Turok have proposed two specific models of this type to study the possibility of a Big Crunch/Big Bang transition. For both models, I will provide a D-brane interpretation of the unbounded potential. In particular, I will show that the AdS boundary conditions of interest cause spherical D-branes to be pushed to the boundary of AdS, and that the corresponding potential agrees with the multi-trace deformation of the boundary field theory

I discuss the basic model of Higgs inflation, with a large non-minimal curvature coupling, from the point of view of effective field theory. It is pointed out that the effective cutoff scale is uncomfortably low compared to the inflation scale, thus rendering these models extremely sensitive to the details of the ultraviolet completion.