Selected Topics in the Large Quantum Number Expansion
Abstract
In this review we study quantum field theories and conformal field theories with global symmetries in the limit of large charge for some of the generators of the symmetry group. At low energy the sectors of the theory with large charge are described by a hybrid form of Goldstone's theorem, involving its relativistic and non-relativistic forms. The associated effective field theory in the infrared allows the computation of anomalous dimensions, and operator product expansion coefficients in a well defined expansion in inverse powers of the global charge. This applies even when the initial theory does not have a reliable semiclassical approximation. The large quantum number expansion complements, and may provide an alternative approach to the bootstrap and numerical treatments. We will present some general features of the symmetry breaking patterns and the low-energy effective actions, and a fairly large number of examples exhibiting the salient features of this method.
Cite
@article{arxiv.2008.03308,
title = {Selected Topics in the Large Quantum Number Expansion},
author = {Luis Álvarez Gaumé and Domenico Orlando and Susanne Reffert},
journal= {arXiv preprint arXiv:2008.03308},
year = {2021}
}
Comments
118 pages. Matched published version in Physics Reports. arXiv admin note: text overlap with arXiv:1711.07990 by other authors