Generalised correlations in disordered dynamical systems: Insights from the many-species Lotka-Volterra model

Fuente: arXiv
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Main Authors: Castedo, Sebastian Holtedahl, Holmes, Joshua, Baron, Joseph William, Galla, Tobias
Format: Preprint
Published: 2024
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author Castedo, Sebastian Holtedahl
Holmes, Joshua
Baron, Joseph William
Galla, Tobias
author_facet Castedo, Sebastian Holtedahl
Holmes, Joshua
Baron, Joseph William
Galla, Tobias
contents In the study of disordered systems, one often chooses a matrix of independent identically distributed interaction coefficients to represent the quenched random couplings between components, perhaps with some symmetry constraint or correlations between diagonally opposite pairs of elements. However, a more general set of couplings, which still preserves the statistical interchangeability of the components, could involve correlations between interaction coefficients sharing only a single row or column index. These correlations have been shown to arise naturally in systems such as the generalised Lotka-Volterra equations (gLVEs). In this work, we perform a dynamic mean-field analysis to understand how single-index correlations affect the dynamics and stability of disordered systems, taking the gLVEs as our example. We show that in-row correlations raise the level of noise in the mean field process, even when the overall variance of the interaction coefficients is held constant. We also see that correlations between transpose pairs of rows and columns can either enhance or suppress feedback effects, depending on the sign of the correlation coefficient. In the context of the gLVEs, in-row and transpose row/column correlations thus affect both the species survival rate and the stability of ecological equilibria.
format Preprint
id arxiv_https___arxiv_org_abs_2409_12751
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Generalised correlations in disordered dynamical systems: Insights from the many-species Lotka-Volterra model
Castedo, Sebastian Holtedahl
Holmes, Joshua
Baron, Joseph William
Galla, Tobias
Disordered Systems and Neural Networks
Populations and Evolution
In the study of disordered systems, one often chooses a matrix of independent identically distributed interaction coefficients to represent the quenched random couplings between components, perhaps with some symmetry constraint or correlations between diagonally opposite pairs of elements. However, a more general set of couplings, which still preserves the statistical interchangeability of the components, could involve correlations between interaction coefficients sharing only a single row or column index. These correlations have been shown to arise naturally in systems such as the generalised Lotka-Volterra equations (gLVEs). In this work, we perform a dynamic mean-field analysis to understand how single-index correlations affect the dynamics and stability of disordered systems, taking the gLVEs as our example. We show that in-row correlations raise the level of noise in the mean field process, even when the overall variance of the interaction coefficients is held constant. We also see that correlations between transpose pairs of rows and columns can either enhance or suppress feedback effects, depending on the sign of the correlation coefficient. In the context of the gLVEs, in-row and transpose row/column correlations thus affect both the species survival rate and the stability of ecological equilibria.
title Generalised correlations in disordered dynamical systems: Insights from the many-species Lotka-Volterra model
topic Disordered Systems and Neural Networks
Populations and Evolution
url https://arxiv.org/abs/2409.12751