Torsion and anomalies in the warped limit of Lifschitz theories

Abstract

We describe the physics of fermionic Lifschitz theories once the anisotropic scaling exponent is made arbitrarily small. In this limit the system acquires an enhanced (Carrollian) boost symmetry. We show, both through the explicit computation of the path integral Jacobian and through the solution of the Wess-Zumino consistency conditions, that the translation symmetry in the anisotropic direction becomes anomalous. This turns out to be a mixed anomaly between boosts and translations. In a Newton-Cartan formulation of the space-time geometry such anomaly is sourced by torsion. We use these results to give an effective field theory description of the anomalous transport coefficients, which were originally computed through Kubo formulas in [1]. Along the way we provide a link with warped CFTsThis work is supported by FPA2015-65480-P and by the Spanish Research Agency (Agencia Estatal de Investigación) through the grant IFT Centro de Excelencia Severo Ochoa SEV2016-0597. The work of C.C. is funded by Fundación La Caixa under “La Caixa-Severo Ochoa” international predoctoral grant. the author would like to thank Karl Landsteiner and Eric Bergshoeff for discussions and comments on the draft. He also would like to thank the organizers of the “Effective Theories of Quantum Phases of Matter” workshop at NORDITA, where part of this work was presente