Theory HEP Seminar

Lessons from Quantum Strings for Quantum Gravity

Yuri Makeenko

ITEP

It is known since 1980s that both lattice regularizations and the KPZ-DDK CFT technique work for bosonic strings only in target-space dimensions d<2. I discuss that the classical string ground state is unstable for d>2, where another quantum ground state has lower energy and is stable under fluctuations for 2<d<26. I consider a higher-derivative correction to the Liouville action emerging from higher orders of the DeWitt-Seeley expansion and show at one loop how it tells the Nambu-Goto and Polyakov strings apart.