Alladi Ramakrishnan Hall

Probing Out-of-Time-Order Correlators

Soumyadeep Chaudhuri

ICTS-TIFR, Bangaluru

In this talk I will present a method to probe the
Out-of-Time-Order Correlators (OTOCs) of a general system by coupling it to
a harmonic oscillator probe. When the system's degrees of freedom are
traced out, the OTOCs imprint themselves on the generalized influence
functional of the oscillator. This generalized influence functional leads
to a local effective action for the probe whose couplings encode OTOCs of
the system. I will focus on the structural features of this effective
action and the constraints on the couplings from microscopic unitarity. I
will also discuss the additional constraints imposed on the effective
couplings of the probe when the system is in a thermal state. Finally, I
will describe a concrete model where all these analyses are applied to
obtain an effective theory of the probe.