Archive: Stochastik Rhein-Main

15.04.2025 Rhein-Main-Kolloquium

Janina Hesse (Leibniz-Institut für Resilienzforschung, Mainz)

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

24.–28.03.2025 Sommer-/Winterschule

Spring School 2025

12.02.2025 Andere Veranstaltungen

Martin Kolb (Universität Paderborn)

Mathematisches Kolloquium TU Darmstadt

04.02.2025 Oberseminar Mainz

Fabio Frommer (Universität Mainz Fachbereich Mathematik)

Solutions of the Kirkwood-Salsburg equations at negative activity

24.01.2025 Rhein-Main-Kolloquium

Yvan Velenik (Universität Genf)
Alexander Glazman (Universität Innsbruck)

RMK Darmstadt

21.01.2025 Oberseminar Mainz

Mareike Fischer (Universität Greifswald)

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

17.01.2025 Rhein-Main-Kolloquium

Christian Mönch (JGU Mainz)
David Belius (UniDistance Suisse)

RMK Mainz 17.01.2025

12.12.2024 Oberseminar Darmstadt

Gianmarco Del Sarto (TU Darmstadt)

Some perspective on climate change through energy balance models

05.12.2024 Oberseminar Darmstadt

Tobias Schmidt (TU Darmstadt)

Enhanced binding of a quantum particle coupled to a scalar quantized field

03.12.2024 Oberseminar Mainz

Sebastian Hummel (ETH Zürich)

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

28.11.2024 Oberseminar Darmstadt

Alexander Drewitz (Universität zu Köln)

Random Walk among Moving Traps

26.11.2024 Oberseminar Mainz

Reinhard Höpfner (Johannes Gutenberg-Universität JGU Mainz)

Circuits von Hodgkin-Huxley-Neuronen

19.11.2024 Oberseminar Mainz

Sascha Franck (Universität Frankfurt)

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

15.11.2024 Rhein-Main-Kolloquium

Christina Goldschmidt (University of Oxford)
Benedikt Stufler (TU Wien)

RMK Frankfurt

07.11.2024 Oberseminar Darmstadt

Noemi Kurt (Goethe-Universität Frankfurt)

Dormancy in population genetics and interacting particle systems

31.10.2024 Oberseminar Darmstadt

David Mitrouskas (Institute of Science and Technology Austria (ISTA))

Semiclassical Dynamics of a Particle in a Quantum Field

24.10.2024 Oberseminar Darmstadt

Benjamin Lees (University of Leeds)

Combinatorial identities from an inhomogeneous Ising chain

18.07.2024 Oberseminar Darmstadt

Jakob Björnberg (Universität Göteborg)

Dimerisation in mirror models and quantum spin chains

12.07.2024 Rhein-Main-Kolloquium

Nicolas Champagnat (Nancy)
Anita Winter (Duisburg-Essen)

RMK Frankfurt

The grapheme-valued Wright-Fisher Diffusion with mutation --- In Athreya, den Hollander and Röllin (2021) models from population genetics were used to de fine stochastic dynamics in the space of graphons that arise as continuum limits of dense graph sequencess. In this talk we extend this framework to a model with mutation. In particular, we define a finite graph valued Markov chain that can be associated with the infinite many alleles model, and establish a diffusion limit as the number of vertices goes to infinity. For that we encode finite graphs as graphemes. Graphems are those graphons that can be represented as a triple consisting of a topological vertex space, an adjacency matrix and a sampling measure. The space of graphons is equipped with convergence of sample subgraph densities. (joint work with Andreas Greven, Frank den Hollander and Anton Klimovsky) -------------------------------------------------------------------- Scaling limits of individual-based models in adaptive dynamics and local extinction of populations (N. Champagnat) --- Starting from an individual-based birth-death-mutation-selection model of adaptive dynamics with three scaling parameters (population size, mutation rate, mutation steps size), we will describe several scaling limits that can be applied to this model to obtain macroscopic models of different natures (PDE, Hamilton-Jacobi equation, stochastic adaptive walks, canonical equation of adaptive dynamics), which allow to characterize the long-term evolution of the population. Motivated by biological criticisms on the time-scale of evolution and the absence of local extinctions in the obtained macroscopic models, we propose new parameter scalings under which we can characterize the evolution of population sizes of the order of $K^\beta$, where $K$ is the order of magnitude of the total population size, and which allows for local extinction of subpopulations. This presentation will gather results obtained with several collaborators: Régis Ferrière, Sylvie Méléard, Amaury Lambert, Viet Chi Tran, Sepideh Mirrahimi, Vincent Hass. Read more

27.06.2024 Oberseminar Darmstadt

David Heson (Mississippi State University)

Computational Methods for Analyzing 1-Dimensional Heisenberg Spin Rings and Similar Systems

Events archive

Events

Oberseminar Mainz

Spring School 2025

Mathematisches Kolloquium TU Darmstadt

Solutions of the Kirkwood-Salsburg equations at negative activity

RMK Darmstadt

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

RMK Mainz 17.01.2025

Some perspective on climate change through energy balance models

Enhanced binding of a quantum particle coupled to a scalar quantized field

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

Random Walk among Moving Traps

Circuits von Hodgkin-Huxley-Neuronen

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

RMK Frankfurt

Dormancy in population genetics and interacting particle systems

Semiclassical Dynamics of a Particle in a Quantum Field

Combinatorial identities from an inhomogeneous Ising chain

Dimerisation in mirror models and quantum spin chains

RMK Frankfurt

Computational Methods for Analyzing 1-Dimensional Heisenberg Spin Rings and Similar Systems

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