Defect dynamics in pulsating active matter
Objectives
Some collective states in active matter exhibit topological properties through the formation of vortices and defects [1-2]. In some living systems, defects have been shown to have important biological functions [3-4]. For instance, the deregulation of periodic beating in cardiac tissues (L3), which signals the onset of heart attacks, can be regarded as a transition between some distinct defect dynamics [5]. In this context, an open challenge is to find strategies to control defect dynamics to mitigate heart rhythm disorder. The goal of this project is to study the topological transitions in a minimal model of deformable particles subject to a periodic driving of their sizes [6, 7]. Such a model of pulsating active matter has already been shown to reproduce the emergence of contraction waves, which organise into various dynamical patterns reminiscent of the phenomenology in contractile tissues [5].
Activities of the Doctoral Candidate
We will rely on recent analytical and numerical methods (T3,9,10; [8-10]) to explore the interplay between structural defects, characterising the packing configurations, and phase defects, characterising the spatial arrangement of particles and their degree of synchronisation; see (T1) particle-based models. In practice, we will combine the expertise of the Fodor [6-7] and Levis [8-10] to quantify and model the defect statistics and topology (T5) in pulsating active matter. Therefore, we aim at providing a synthetic understanding for the mechanisms of the underlying topological transitions, which should eventually inform some concrete strategies to control pattern formation in contractile tissues.
Facilities Provided
Access to computing facilities for numerical work, including high performance computing.
Employment Contract
The Doctoral Candidate will be employed consistently with the terms of the Doctoral Network funding, please see Eligibility and How to Apply for further details.
Period of Doctorate and Funding
Doctorates at University of Barcelona take between 3 and 4 years. Unspent local CAFE-BIO funds will be used to support the Doctoral Candidate in year 4 as required.
References
[1] Shankar, S, et al. (2022) Nat Phys Rev 4:380;
[2] Tubiana, L, et al. (2024) Phys Rep 1075:1;
[3] Kawaguchi, K, et al. (2017) Nature 545:327;
[4] Copenhagen, K, et al. (2021) Nat Phys 17:211;
[5] Karma, A. (2013)Annu Rev Condens Matter Phys 4:313;
[6] Zhang, Y, & Fodor, É (2023) Phys Rev Lett 131:238302;
[7] Piñeros, WD, & Fodor, É. (2024) arXiv:2403.16961;
[8] Digregorio, D, et al (2022) Soft Matter 18:566;
[9] Rouzaire, Y, & Levis, D. (2021) Phys Rev Lett 127:088004;
[10] Rouzaire, Y, et al. (2024) arXiv:2407.19603