BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//talks.bham.ac.uk//v3//EN
BEGIN:VEVENT
CATEGORIES:Theoretical Physics Seminars
SUMMARY:Equilibrium and nonequilibrium description of nega
tive temperature states in a one-dimensional latti
ce using a wave kinetic approach - Davide Proment\
, University of East Anglia
DTSTART:20230427T121500Z
DTEND:20230427T133000Z
UID:TALK5270AT
URL:/talk/index/5270
DESCRIPTION:We predict negative temperature states in the disc
rete nonlinear SchÃ¶dinger (DNLS) equation as exact
solutions of the associated wave kinetic equation
. Within the wave kinetic approach\, we define an
entropy that results monotonic in time and reaches
a stationary state\, that is consistent with clas
sical equilibrium statistical mechanics. We also p
erform a detailed analysis of the fluctuations of
the actions at fixed wave numbers around their mea
n values. We give evidence that such fluctuations
relax to their equilibrium behavior on a shorter t
imescale than the one needed for the spectrum to r
each the equilibrium state. Numerical simulations
of the DNLS equation are shown to be in agreement
with our theoretical results. The key ingredient f
or observing negative temperatures in lattices cha
racterized by two invariants is the boundedness of
the dispersion relation.\n(Based on the joint wor
k M. Onorato\, et al.\, PRE 105\, 014206\, 2022)
LOCATION:Theory Library
CONTACT:Dr Hannah Price
END:VEVENT
END:VCALENDAR