BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20251124T201153EST-2860D24jzl@132.216.98.100 DTSTAMP:20251125T011153Z DESCRIPTION:Title: About the multivariate fractional Brownian motion.\n\nAb stract: Since the pioneering work by Mandelbrot and Van Ness in 1968\, the fractional Brownian motion (fBm) became a classical stochastic process fo r modelling one-dimesional self-similar or long-memory processes. In parti c- ular\, we have recently applied this model to characterize the regulari ty and dependence of fMRI signals acquired in the brain of resting-state p atients. This analysis was conducted independently on each region of inter est of the brain. Despite the first analysis showed interesting results\, the model needed to be improved in order to take into account the possible connectivity of regions of interest. In this talk\, we present an extensi on of the fBm to the multivariate case that may be well-suited to such dat a: the multivariate fractional Brownian motion (mfBm) characterized in par ticular by p Hurst exponents. After recalling some facts about the fBm\, I will state some theoretical properties of the mfBm: (cross)-correlation\, spectral density matrix\, wavelet analysis\, existence conditions. Then\, I will detail how we can exactly and quickly generate sample paths of the mfBm. Finally\, we will focus on the statistical inference and mainly on the joint estimation of the fractal exponents (H1\, ...\, Hp) using a disc rete variations techniques.\n DTSTART:20190221T203000Z DTEND:20190221T213000Z LOCATION:Room PK-5115 \, CA\, UQAM\, Seminar STATQAM SUMMARY:Jean-François Coeurjolly\, UQAM URL:/mathstat/channels/event/jean-francois-coeurjolly- uqam-294776 END:VEVENT END:VCALENDAR