An unexpected bridge between toy models of glasses and of black holes

Jorge Kurchan (LPENS, ENS)

A `toy' model of a fermionic spin-glass (the Sachdev Ye Kitaev model) can be shown to have a low-temperature limit characterised by a linear temperature dependence of the specific heat, finite entropy, and maximal possible chaoticity. These are properties expected from quantum Black Holes.

At the bottom of this is a (quasi) invariance with respect deformations of time, so that the low energy excitations
are in fact time-reparametrizations.

Remarkably, the very same invariance appears generically in glassy dynamics, and it dominates the evolution of slow modes.

A direct and elementary connection may be established between these two formal situations, but the physical connection
is still very intriguing.