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arXiv · 2311.04564

Free fermions, KdV charges, generalised Gibbs ensembles, modular transforms and line defects

Max Downing·Gerard Watts
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Abstract

In this paper we return to the question of the modular properties of a generalised Gibbs ensemble of a single free fermion. We extend our previous proposals to a GGE containing an arbitrary number of conserved charges and provide a physical interpretation of the result in terms of a line defect. The defect description perfectly explains the product formula for the modular transformation we found previously. We also give a proposal for a Hamiltonian approach to the line defect.

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Max Downing, Gerard Watts. 2023-11-08. Free fermions, KdV charges, generalised Gibbs ensembles, modular transforms and line defects. https://arxiv.org/abs/2311.04564

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