BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20250810T231945EDT-0329zCsZo9@132.216.98.100 DTSTAMP:20250811T031945Z DESCRIPTION:Title: Variance reduction by occluding a Markov chain.\n\nAbstr act:\n\nStochastic algorithms which simulate random variables/processes on a computer to estimate intractable quantities are ubiquitous in Statistic s and elsewhere. One such method is Markov chain Monte Carlo which\, under mild conditions\, offer asymptotical (in time) guarantees. In this talk\, we define infinitely many stopping times at which an ergodic Markov chain is occluded by a (conditionally) independent process. The resulting proce ss\, called the occluded process\, is not Markov\, but provided that the s topping times/independent process are cleverly defined\, we show that it i s ergodic. One particularly powerful way to define the stopping times/inde pendent process leverages the recent advances in ML regarding approximatio ns of probability distributions (divergence minimization\, normalizing flo ws\, etc.). We discuss the variance reduction effect of the occluded proce ss through some illustrations and (weak) theoretical results in some limit ing regime.\n\nSpeaker\n\nFlorian Maire is an Associate Professor at Unive rsité de Montréal\, which he joined in 2018 after a PhD from Paris 6 and T elecom SudParis and a Postdoc at University College Dublin. His research i nterests are mostly in computational statistics and stochastic optimizatio n.\n DTSTART:20240920T193000Z DTEND:20240920T203000Z LOCATION:Room 1104\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:Florian Maire(Université de Montréal) URL:/channels/channels/event/florian-maireuniversite-d e-montreal-359670 END:VEVENT END:VCALENDAR