Edouard Brezin - LPT ENS
Wednesday, May 3, 10:45AM EDT (Zoom meeting starts at 10:30 EDT)
Instantons versus renormalons: Can one make sense of the epsilon-expansion?
Divergent perturbation expansions without small parameter, such as the epsilon-expansion, require a control of their large order behavior. A semi-classical picture based on instanton solutions conflicts with the phenomenon of renormalons, specific to renormalizable theories. An explicit solution allows one to settle this controversy. (Based on arxiv 2301.01174; to be published in a book in memory of Michael Fisher edited by A.Aharony et al. )