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Spontaneous symmetry breaking in pure 2D Yang-Mills theory

High Energy Physics - Theory 2020-05-28 v3

Abstract

We consider purely topological 22d Yang-Mills theory on a torus with the second Stiefel-Whitney class added to the Lagrangian in the form of a θ\theta-term. It will be shown, that at θ=π\theta=\pi there exists a class of SU(2N)/Z2SU(2 N)/\mathbb{Z}_2 (N>1N>1) gauge theories with a two-fold degenerate vacuum, which spontaneously breaks the time reversal and charge conjugation symmetries. The corresponding order parameter is given by the generator O\mathcal{O} of the ZN\mathbb{Z}_N one-form symmetry.

Keywords

Cite

@article{arxiv.1911.03494,
  title  = {Spontaneous symmetry breaking in pure 2D Yang-Mills theory},
  author = {Gleb Aminov},
  journal= {arXiv preprint arXiv:1911.03494},
  year   = {2020}
}

Comments

The ambiguity between the second Stiefel-Whitney class $w_2$ and an invariant of $PSU(N)$ bundles $u_2$ was removed. Conclusion section and more references were added in version 3