SKM 2023 – wissenschaftliches Programm
DY 33.4: Vortrag
Mittwoch, 29. März 2023, 15:45–16:00, ZEU 250
Hierarchical interactions in complex ecosystems — •Lyle Poley1, Joseph W. Baron3, and Tobias Galla1,2 — 1Theoretical Physics, Department of Physics and Astronomy, School of Natural Sciences, The University of Manchester, Manchester M13 9PL, UK — 2Instituto de Física Interdisciplinar y Sistemas Complejos IFISC (CSIC-UIB), 07122 Palma de Mallorca, Spain — 3Laboratoire de Physique Statistique, École Normale Supérieure (ENS), Paris Sciences et Lettres (PSL) Research University, Sorbonne Université, 75005 Paris, France
In the analysis of complex ecosystems it is common to use random interaction coefficients, often assumed to be such that all species are statistically equivalent. We relax this assumption by imposing hierarchical inter-species interactions, which we incorporate into a generalised Lotka-Volterra dynamical system. These interactions impose a hierarchy in the community. Species benefit more, on average, from interactions with species below them in the hierarchy than from interactions with those above.
Using analytical tools from the theory of disordered systems, most notably path-integrals and dynamic mean-field theory, we demonstrate that a stronger hierarchy stabilises the community by reducing the number of species in the surviving community. We will also show that the probability of survival for a given species is dependent on its position in the hierarchy.
Reference: Poley L, Baron J W and Galla T Generalised Lotka-Volterra model with hierarchical interactions 2022 arXiv:2208.01569