Archive: Stochastik Rhein-Main

18.07.2023 Oberseminar Mainz

Andreas Klippel (TU Darmstadt)

Comparison of the random loop model to percolation and infinite loops in the random link model

07.11.2023 Oberseminar Mainz

Marco Seiler (Goethe-Universität Frankfurt/M.)

Spatial Invasion of Cooperative Parasites

07.05.2024 Oberseminar Mainz

Prof. Dr. Steffen Dereich (Universität Münster)

New error bounds for the Adam optimisation algorithm

In this talk, I will give an introduction concerning the training of artifcial neural networks based on stochastic gradient descent algorithms. Whereas there are various approaches for carrying out an error analysis for classical stochastic gradient descent, significantly less is known for more elaborate algorithms such as the Adam algorithm. Recently, we established a new approach which allows us to provide error estimates and to reduce this gap. The talk is based on joint work with Arnulf Jentzen. Read more

28.05.2024 Oberseminar Mainz

Stein Andreas Bethuelsen (University of Bergen)

Mixing for Poisson representable processes and the contact process

In this talk I will present some new insights on so-called Poisson representable processes, a general class of {0,1}-valued processes recently introduced by Forsström, Gantert and Steif. Particularly, I will discuss a new characteristic of these in terms of certain mixing properties. As an application thereof, I will argue that the upper invariant measure of the contact process on Z^d is not Poisson representable, thereby answering a question raised in the above mentioned work. This relies on the upper invariant measure satisfying certain directional mixing properties, but not their spatial equivalent. Moreover, the general approach extends to other processes having similar properties, such as the plus phase of the Ising model on Z^2 in the phase transition regime. Read more

04.06.2024 Oberseminar Mainz

Samuel Modee (University of Bergen)

Some rigorous results on the zombie infection model

The so-called zombie infection model is a one-parameter family of interacting particle systems introduced in the physics literature in the 2010’s. This model can be seen as a natural hybrid between a SIR infection model and the bias-voter model. After a brief survey on the basics of this model, we present in this talk some rigorous results, focusing on monotonicity properties and bounds on the probability of a zombie invasion. This is based on joint work, in progress, with Erik Broman and Stein Andreas Bethuelsen. Read more

19.11.2024 Oberseminar Mainz

Sascha Franck (Universität Frankfurt)

On the spread of an infection in a spatially distributed host population with host immunity

26.11.2024 Oberseminar Mainz

Reinhard Höpfner (Johannes Gutenberg-Universität JGU Mainz)

Circuits von Hodgkin-Huxley-Neuronen

03.12.2024 Oberseminar Mainz

Sebastian Hummel (ETH Zürich)

Multi-Type Birth-Death Processes with Mean-Field Interactions for B-cell Phylodynamics

21.01.2025 Oberseminar Mainz

Mareike Fischer (Universität Greifswald)

On the reliability of Maximum Parsimony for encoding and reconstructing phylogenetic trees

04.02.2025 Oberseminar Mainz

Fabio Frommer (Universität Mainz Fachbereich Mathematik)

Solutions of the Kirkwood-Salsburg equations at negative activity

15.04.2025 Oberseminar Mainz

Réka Szabó (University of Groningen)

Oberseminar Mainz

How single cell properties can change network synchronization: The saddle-node loop bifurcation in neuron models - Neurons have traditionally been classified into two types depending on their frequency-input curve. Both types are associated with a particular dynamic transition from rest to spiking. Our work highlights a third transition, for which we found experimental evidence in hippocampal slices. For typical Hodgkin-Huxley-like neuron model, we present a universal bifurcation structure, with the separation of timescale between voltage and ion channel dynamics as one of the bifurcation parameters. We predict that the strongest changes in synchronization with small parameter changes occur at a particular co-dimension two bifurcation, the saddle-node loop bifurcation, and we present characteristics of this transition, from changes in firing rate to phase response curve and synchronization. We will conclude with a short overview over our current research on stress resilience. Read more

08.07.2025 Oberseminar Mainz

Réka Szabó (University of Groningen)

Percolation on the stationary distributions of the voter model with stirring

Events archive

Events

Comparison of the random loop model to percolation and infinite loops in the random link model

Spatial Invasion of Cooperative Parasites

New error bounds for the Adam optimisation algorithm

Mixing for Poisson representable processes and the contact process

Some rigorous results on the zombie infection model

On the spread of an infection in a spatially distributed host population with host immunity

Circuits von Hodgkin-Huxley-Neuronen

Multi-Type Birth-Death Processes with Mean-Field Interactions for B-cell Phylodynamics

On the reliability of Maximum Parsimony for encoding and reconstructing phylogenetic trees

Solutions of the Kirkwood-Salsburg equations at negative activity

Oberseminar Mainz

Percolation on the stationary distributions of the voter model with stirring

Overview

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