Stationary broken parity states in active matter models

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Frohoff-Hülsmann, Tobias, Holl, Max Philipp, Knobloch, Edgar, Gurevich, Svetlana V., Thiele, Uwe
Format: Preprint
Published: 2022
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916916509016064
author Frohoff-Hülsmann, Tobias
Holl, Max Philipp
Knobloch, Edgar
Gurevich, Svetlana V.
Thiele, Uwe
author_facet Frohoff-Hülsmann, Tobias
Holl, Max Philipp
Knobloch, Edgar
Gurevich, Svetlana V.
Thiele, Uwe
contents We demonstrate that several nonvariational continuum models commonly used to describe active matter as well as other active systems exhibit nongeneric behavior: each model supports asymmetric but stationary localized states even in the absence of pinning at heterogeneities. Moreover, such states only begin to drift following a drift-transcritical bifurcation as the activity increases. Asymmetric stationary states should only exist in variational systems, i.e., in models with gradient structure. In other words, such states are expected in passive systems, but not in active systems where the gradient structure of the model is broken by activity. We identify a "spurious" gradient dynamics structure of these models that is responsible for this nongeneric behavior, and determine the types of additional terms that render the models generic, i.e., with asymmetric states that appear via drift-pitchfork bifurcations and are generically moving. We provide detailed illustrations of our results using numerical continuation of resting and steadily drifting states in both generic and nongeneric cases.
format Preprint
id arxiv_https___arxiv_org_abs_2205_14364
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Stationary broken parity states in active matter models
Frohoff-Hülsmann, Tobias
Holl, Max Philipp
Knobloch, Edgar
Gurevich, Svetlana V.
Thiele, Uwe
Soft Condensed Matter
Pattern Formation and Solitons
We demonstrate that several nonvariational continuum models commonly used to describe active matter as well as other active systems exhibit nongeneric behavior: each model supports asymmetric but stationary localized states even in the absence of pinning at heterogeneities. Moreover, such states only begin to drift following a drift-transcritical bifurcation as the activity increases. Asymmetric stationary states should only exist in variational systems, i.e., in models with gradient structure. In other words, such states are expected in passive systems, but not in active systems where the gradient structure of the model is broken by activity. We identify a "spurious" gradient dynamics structure of these models that is responsible for this nongeneric behavior, and determine the types of additional terms that render the models generic, i.e., with asymmetric states that appear via drift-pitchfork bifurcations and are generically moving. We provide detailed illustrations of our results using numerical continuation of resting and steadily drifting states in both generic and nongeneric cases.
title Stationary broken parity states in active matter models
topic Soft Condensed Matter
Pattern Formation and Solitons
url https://arxiv.org/abs/2205.14364