Archive: Stochastik Rhein-Main

28.05.2021 Stochastik-Kolloquium Frankfurt

Dr. Jon Warren (Department of Statistics, University of Warwick)

A family of local times studied as a Markov process

A limit theorem for the ρ-length of random functional graphs with fixed degree sequences

An introduction to log-correlated fields and multiplicative chaos

B cell phylodynamics and mean-field multi-type birth and death processes

No knowledge of biology will be necessary to understand this talk. Germinal centers (GC) are micro-anatomical structures that transiently form in lymph nodes during an adaptive immune response. In a GC, B cells—the cells that make antibodies—diversify and compete based on the ability of the antibodies they express to recognize a foreign antigen molecule. As GC B cells proliferate, they undergo targeted mutations in the genomic locus encoding the antibody protein that can modify its antigen binding affinity. Via signaling from other GC cell types, the GC can monitor the binding phenotype of the B cell population it contains and provide survival signals to B cells with the highest-affinity antibodies (i.e., birth and death rates depend on type). Motivated by this mechanism, we develop a mean-field model that couples the birth and death rates in a focal multi-type birth and death process (MTBDP) with D types to the empirical distribution of states—i.e., the mean-field over an exchangeable system of N replica MTBDPs. The empirical distribution process of the N replicas converges to a deterministic probability measure-valued flow as N goes to infinity. In the limit, the focal process evolves as a multi-type birth and death process with rates governed by the probability measure-valued flow which is in turn the flow of one-dimensional marginal distributions of the focal process. Individual focal processes become independent in the limit and this holds out the hope of inference being feasible for this model. This is joint work with William S. DeWitt, Ella Hiesmayr, and Sebastian Hummel. Read more

10.05.2017 Stochastik-Kolloquium Frankfurt

Prof. Dr. Hsien-Kuei Hwang (Academia Sinica, Taipeh)

Coin-tossing in Algorithmics

Crossing a fitness valley as a metastable transition in a stochastic population model

Detecting Joint Pauses in Parallel Point Processes

Prof. Dr. Sylvie Roelly (Universität Potsdam)

Die Renaissance des Werkes des Mathematikers Vincent Doeblin

David Damanik (Rice University, Houston)

Extra-Kolloquium: Analysis & Stochastik

Dr. Viet Chi TRAN (Université des Sciences et Technologies de Lille)

Hawkes processes with self-excitation and inhibition

Prof. Dr. Dirk Metzler (FB Biologie/ LMU München)

Hybridzone zwischen Rabenkrähen und Nebelkrähen: Artbildung allein durch Paarungspräferenzen?

Dr. Arash Jamshidpey (IMPA Rio de Janeiro / Carleton University Ottawa)

Interacting populations in fluctuating environments

Prof. Dr. Sebastian Mentemeier

Limit theorems for recursive cell-splitting schemes

Metrische Multidimensionale Skalierung

Prof. Dr. Sebastian Doehler (Hochschule Darmstadt)

New false discovery rate controlling procedures for discrete data

Karl-Theodor Sturm (Universität Bonn)

Optimal transport, heat flow, and Ricci curvature on metric measure spaces

Jean-Francois Le Gall (Université Paris-Sud and Institut universitaire de France)

Random planar geometry

Rekonstruktion zufällig verkürzter Zeichenketten