BEGIN:VCALENDAR VERSION:2.0 PRODID:-//132.216.98.100//NONSGML kigkonsult.se iCalcreator 2.20.4// BEGIN:VEVENT UID:20260427T033145EDT-5177zSjkOT@132.216.98.100 DTSTAMP:20260427T073145Z DESCRIPTION:Title: Asymptotic behavior of the hierarchical Pitman-Yor proce ss.\n\nAbstract: The Pitman-Yor process is a discrete random measure speci fied by a concentration parameter\, discount parameter\, and base distribu tion\, and is used as a fundamental prior in Bayesian nonparametrics. The hierarchical Pitman-Yor process (HPYP) is a generalization obtained by ran domizing the base measure through a draw from another Pitman-Yor process. It is motivated by the study of groups of clustered data\, where the group specific Pitman-Yor processes are linked through an intergroup Pitman-Yor process. Setting both discount parameters to zero gives the hierarchical Dirichlet process (HDP)\, first introduced by Teh et al. in the machine le arning literature.\n \n In this talk\, we discuss our recent work on the asy mptotic behavior of the HPYP and HDP. In the first part\, we establish lim it theorems associated with the power sum symmetric polynomials for the ve ctor of weights of the HDP as the concentration parameters tend to infinit y. These objects are related to the homozygosity in population genetics\, the Simpson diversity index in ecology\, and the Herfindahl-Hirschman inde x in economics. In the second part\, we consider a random sample of size $ N$ from a population whose type distribution is given by the vector of wei ghts of the HPYP and study the large $N$ asymptotic behavior of the number of clusters in the sample. This talk is based on joint work with Stefano Favaro and Shui Feng.\n DTSTART:20260319T153000Z DTEND:20260319T163000Z LOCATION:Room 920\, Burnside Hall\, CA\, QC\, Montreal\, H3A 0B9\, 805 rue Sherbrooke Ouest SUMMARY:J E Paguyo (McMaster University) URL:/mathstat/channels/event/j-e-paguyo-mcmaster-unive rsity-371987 END:VEVENT END:VCALENDAR