Theory HEP Seminar

Time-Dependent Backgrounds of 1+1 Dimensional String Theory

Bruno Balthazar

NYU

Time-dependent backgrounds of string theory can reveal properties of quantum gravity in cosmological and black hole backgrounds. However, despite their importance, examples of such backgrounds are scarce. In this talk, I will describe a family of time-dependent backgrounds of 1+1 dimensional string theory. In these examples, the Liouville wall accelerates and approaches a final velocity at future infinity. This final velocity can be greater than the speed of light, in which case asymptotic null infinity is shielded by the Liouville wall. I will compute scattering and particle production amplitudes in these backgrounds in the region in parameter space where the wall remains timelike, and discuss the continuation of this picture to the spacelike regime.