https://neckpinch.com/authors/ben-hoare/New arXiv papers by Ben Hoare, from Neckpinch Tue, 10 Nov 2026 04:10:28 GMT https://neckpinch.com/papers/1907.04737/arxiv:1907.04737Wed, 10 Jul 2019 00:00:00 GMTBen Hoare, Nat Levine, Arkady A. Tseytlin — Classically integrable σ-models are known to be solutions of the 1-loop RG equations, or "Ricci flow", with only a few couplings running. In some of the simplest examples of integrable deformations we find that in order to preserve this property at 2 (and higher) loops the classical σ-model should be corrected by quantum counterterms. The pattern is similar to that of effective σ-models associated to gauged WZW theories. We consider in detail the examples of the η-deformation of S² ("sausage model") and H², as well as the closely related λ-deformation of the SO(1,2)/SO(2) coset. We also point out that similar counterterms are required in order for non-abelian duality to commute with RG flow beyond the 1-loop order.Ricci flowPhysics