Normal state properties of quantum-critical metals at finite temperatures*

Recent years have seen an intense effort to study models of fermionic quantum criticality and superconductivity via sign-problem-free quantum Monte Carlo. These studies found a number of puzzling features, which are in qualitative disagreement with quantum-critical-scaling theories and, in particular, cast doubt on the validity of Eliashberg-type approaches to quantum criticality. I will discuss how thermal fluctuations destroy the nice scaling properties of quantum-critical systems and show that after generalizing Eliashberg theory to account for thermal fluctuations many of the qualitative disagreements vanish. This work provides concrete guidelines for analyzing ongoing numerical work.