BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//wp-events-plugin.com//6.4.7.2//EN
TZID:Europe/Paris
X-WR-TIMEZONE:Europe/Paris
BEGIN:VEVENT
UID:0-844@lptms.universite-paris-saclay.fr
DTSTART;TZID=Europe/Paris:20221115T110000
DTEND;TZID=Europe/Paris:20221115T120000
DTSTAMP:20221110T133932Z
URL:http://www.lptms.universite-paris-saclay.fr/seminars/seminaire-du-lptm
 s-benjamin-walter/
SUMMARY:Séminaire du LPTMS : Benjamin Walter (Imperial College London) - S
 alle des séminaires du FAST et du LPTMS\, bâtiment Pascal n°530 - 15 No
 v 22 11:00
DESCRIPTION:First passage problems in classical and quantum processes\nBenj
 amin Walter (Imperial College London)\n\nHybrid: onsite seminar + zoom.\nR
 egister in advance for this meeting:\nhttps://cnrs.zoom.us/meeting/registe
 r/tJMtc-GtrzoiH91Fdg5TmtBM4LKkuzB-TEWJ \nAfter registering\, you will rece
 ive a confirmation email containing information about joining the meeting.
 \n\n\nIn the first part of my talk I discuss the problem of first-passage 
 times of a certain class of non-Markovian “active thermal” processes [
 1\,2]. These are one-dimensional stochastic processes that are driven by b
 oth an uncorrelated (thermal) noise as well as a self-correlated (“activ
 e”) noise. I present a field theoretic perturbation theory\, valid in th
 e low-activity regime\, which systematically computes the corrections to t
 he survival probability\, and hence allows one to extract distributions of
  first-passage times\, running maxima and mean range via some simple relat
 ions. I further give a brief outlook on current work regarding processes d
 riven by fractional Gaussian noise.\n\nIn the second part of my talk\, I p
 resent some preliminary findings of an ongoing research project [3] studyi
 ng the first detection time [4] of a many body quantum system. The first d
 etection time is the first time that a quantum system is observed to be in
  a predefined state under repeated projective measurements. We study N\, p
 ossibly infinite\, free fermions which are arranged adjacently on a linear
  lattice. Under periodical projective measurements\, performed at a period
  of \\tau\, we study the statistics of the return probability F_k(\\tau)\;
  the probability to find the system in its initial state for the first tim
 e at the k-th attempt of measurement. The statistics of F_k(\\tau) depend 
 non-trivially on \\tau\, and we provide some analytical estimates based on
  recently found results on the N-fermion return amplitude [5]\, which are 
 compared to exact computations.\n\n(Jointly with Andrea Gambassi\, Gabriel
 e Perfetto\, Gunnar Pruessner and Guillaume Salbreux) \n\n\nReferences\n\n
 1 B. Walter\, G. Pruessner\, G. Salbreux\, Phys. Rev. Res. 3\, 013075 (202
 1)\n2 B. Walter\, G. Pruessner\, G. Salbreux\, Phys. Rev. Res.\, in print 
 (2022)\n3 B. Walter\, G. Perfetto\, A. Gambassi\, In preparation\n4 H. Fri
 edman\, D. A. Kessler\, E. Barkai\, Phys. Rev. E \, 95\, 032141 (2017)\n5 
 P. L. Krapivsky\, J. M. Luck\, K Mallick\, Journal of Statistical Mechanic
 s: Theory and Experiment 2018\, 023104 (2018)\n
CATEGORIES:seminars
LOCATION:Salle des séminaires du FAST et du LPTMS\, bâtiment Pascal n°53
 0\, rue André Riviere\, Orsay\, 91405\, France
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=rue André Riviere\, Orsay\
 , 91405\, France;X-APPLE-RADIUS=100;X-TITLE=Salle des séminaires du FAST 
 et du LPTMS\, bâtiment Pascal n°530:geo:0,0
END:VEVENT
BEGIN:VTIMEZONE
TZID:Europe/Paris
X-LIC-LOCATION:Europe/Paris
BEGIN:STANDARD
DTSTART:20221030T020000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
END:STANDARD
END:VTIMEZONE
END:VCALENDAR