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arXiv · 1810.03118

Spectral Representation of Thermal OTO Correlators

Soumyadeep Chaudhuri·Chandramouli Chowdhury·R. Loganayagam
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Abstract

We study the spectral representation of finite temperature, out of time ordered (OTO) correlators on the multi-time-fold generalised Schwinger-Keldysh contour. We write the contour-ordered correlators as a sum over time-order permutations acting on a funda- mental array of Wightman correlators. We decompose this Wightman array in a basis of column vectors, which provide a natural generalisation of the familiar retarded-advanced basis in the finite temperature Schwinger-Keldysh formalism. The coefficients of this de- composition take the form of generalised spectral functions, which are Fourier transforms of nested and double commutators. Our construction extends a variety of classical results on spectral functions in the SK formalism at finite temperature to the OTO case.

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Soumyadeep Chaudhuri, Chandramouli Chowdhury, R. Loganayagam. 2018-10-07. Spectral Representation of Thermal OTO Correlators. https://doi.org/10.1007/jhep02(2019)018

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