Quantum Fields and Strings

I review our recent work on confinement in 2+1 Yang Mills theory using Karabali-Nair variables. I'll discuss our successful prediction of the glueball spectrum, including the manifestations of the QCD string.

Given the difficulty of studying time-dependent processes in string theory, closed string tachyon condensation problems are often modelled by the process of renormalization group flow on the world-sheet. But what is the quantitative relation between these two processes? In this talk I will give a partial answer to this question, and discuss what it teaches us about closed string tachyon dynamics.