报告题目：Stochastic population dynamics

报告人：Uwe C. Täuber 教授，Virginia Tech（弗吉尼亚理工大学）

报告时间：2024年11月1日（星期五），9:30-10:30

报告地点：致知楼3328会议室

报告摘要：

Theoretical physics provides a toolbox for quantitative analysis for many paradigmatic models employed in biology and ecology. Dynamical models of interacting populations have recently become of fundamental interest for spontaneous pattern formation and other intriguing features in non-equilibrium statistical physics. Stochastic, spatially extended models for predator-prey interaction display spatio-temporal structures that are not captured by the Lotka-Volterra mean-field rate equations. These activity fronts induce persistent correlations among predators and prey that are amenable to field-theoretic analysis. Introducing local restrictions on the prey population induces predator extinction. The critical dynamics at this continuous absorbing state transition is governed by the scaling exponents of critical directed percolation. This talk will address several biologically motivated model variants: A periodically varying carrying capacity that captures seasonally oscillating resource availabilty for the prey further stabilizes the two-species coexistence regime and can resonantly induce population enhancement. One may also implement environmental variability through spatially varying reaction rates: Fluctuations in rare favorable regions cause a remarkable increase in both predator and prey populations. Intriguing evolutionary features are observed when variable interaction rates are affixed to individual particles and inherited to their offspring. Vulnerable finite ecosystems subject to stochastic fixation or extinction may be efficiently stabilized through diffusive coupling to stable adjacent regions and particle influx across the interfaces. Systems with three cyclically competing species akin to spatial rock-paper-scissors games may display striking spiral patterns, yet conservation laws can prevent such noise-induced structure formation. The related susceptible-infected-recovered (SIR) model and various refinements are widely employed to study infectious disease spreading.

Overview references:

U. Dobramysl, M. Mobilia, M. Pleimling, and U.C.T., J. Phys. A: Math. Theor. 51, 063001 (2018); arXiv:1708.07055.

U.C.T., in "Order, disorder, and criticality. Advanced problems of phase transition theory and complex systems", Vol. VIII, Y. Holovatch (ed.), Chap. 2, 67 (World Scientific 2024); arxiv:2405.05006.

报告人简介：

Uwe Claus Täuber, 美国弗吉尼亚理工大学物理系教授，国际著名理论物理学家。1992年获慕尼黑工业大学博士学位，1993-1997年先后于哈佛大学和牛津大学进行博士后研究，1997年起先后在慕尼黑工业大学和弗吉尼亚理工大学任职，2016-2022年任弗吉尼亚理工大学软物质和生物物理中心主任。 2013年当选为美国物理学会会士。曾任Physical Revew E、Journal of Physics A等杂志编委，并于2021-2023年任Physical Review E主编。主要研究领域包括平衡和非平衡系统的相变和临界行为以及统计物理理论在凝聚态系统、生物系统和复杂系统中的应用。其研究为非平衡临界现象理论奠定了重要的基础，所著《Critical Dynamics：A Field Theory Approach to Equilibrium and Non-Equilibrium Scaling Behavior》一书已成为该领域的重要参考。