2019/07/22 by Cardella, Matteo A.
#FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Statistical Mechanics (cond-mat.stat-mech) #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.1907.09570
The Sachdev-Ye-Kitaev model spectral form factor exhibits absence of information loss in the form of a ramp and a plateau, that are typical of random matrix theory. In a large N collective fields description, the ramp was reproduced by Saad, Shenker and Stanford \citeSaad:2018bqo, by replica symmetry breaking saddles for a connected component of the analytically continued to real times thermal partition function two point function. We derive a two sides Schwarzians effective action for fluctuations around the ramp critical saddles, by adapting to the two replica system a method by Kitaev and Suh \citeKitaev:2017awl for studying non linear responses to the conformal breaking kinetic operator in regular SYK. Our result confirms \citeSaad:2018bqo, where the form of the action was obtained by assuming locality.