Hydrodynamic Equations for Flocking Models without Velocity Alignment

Peruani, Fernando

doi:10.7566/jpsj.86.101010

Cited by 12 publications

(7 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this loop structure seems shrinking and unstable for longer time. The similar loop structure is observed transiently in the numerical simulation of the self-propelled system with the visual corn [5,46].…”

Section: Loop Formationsupporting

confidence: 73%

See 1 more Smart Citation

Gliding filament system giving both global orientational order and clusters in collective motion

et al. 2020

View full text Add to dashboard Cite

Active matter consists of self-propelled elements exhibits fascinating collective motions ranging from biological to artificial systems. Among wide varieties of active matter systems, reconstituted bio-filaments moving on molecular motor turf interacting purely by physical interactions provides the fundamental test ground for understanding biological motility. However, for the emergence of ordered patterns such as polar pattern, swirls, clusters, and density wave in actomyosin motility assay, multi-filament collisions are required instead of binary collision which is often assumed in kinetic theory. Similarly, for microtubules driven by kinesin motors to produce nematic ordered state, depletion agents or binding molecules are required to introduce strong alignment effects between filaments. Thus, whether simple physical interactions during collisions such as steric effect without depletion nor binding agents are sufficient or not for producing ordered patterns in motility assays remains still elusive. In this article, we constructed a motility assay purely consists of kinesin motor and microtubule in which the frequency of binary collision can be controlled without using depletion nor binding agents. By controlling strength of steric interaction and density of microtubules, we found different states; disordered state, long-range orientationally ordered state, liquid-gas-like phase separated state, and transitions between them. We found that a balance between cross over and aligning events in collisions controls transition from disorder to global ordered state, while excessively strong steric effect leads to the phase separated clusters. Furthermore, macroscopic chiral symmetry breaking observed as a global rotation of nematic order observed in this experiment could be attributed to the chirality at molecular level. Numerical simulations in which we change strength of volume exclusion reproduce these experimental results. Moreover, it reveals the transition from long-range alignment to nematic bands then to aggregations. This study may provide new insights into dynamic ordering by self-propelled elements through a purely physical interaction.

show abstract

Section: Loop Formationsupporting

confidence: 73%

“…The similar loop structure is observed transiently in the numerical simulation of the self-propelled system with the visual corn [5,46].…”

Section: Loop Formationsupporting

confidence: 73%

Gliding filament system giving both global orientational order and clusters in collective motion

et al. 2020

View full text Add to dashboard Cite

show abstract

“…By construction, this model does not possess velocity-velocity interactions and thus, there is no built-in microscopic interaction rule with either polar or apolar symmetry. And yet, we have proved that in this active model, polar and nematic (velocity) order spontaneously emerge in different areas of the parameter space in the absence of action-reaction symmetry [22,23]. This is in sharp contrast with what it is observed in active systems with velocity alignment [11][12][13][24][25][26][27][28][29][30][31][32][33][34][35], where the emergence of polar order requires a microscopic polar alignment rule [11] and nematic order, a microscopic nematic alignment rule [30,32] (see also [42]).…”

Section: Introductionmentioning

confidence: 65%

Phase separation and emergence of collective motion in a one-dimensional system of active particles

Barberis

Peruani

2019

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

We study numerically a one-dimensional systems of self-propelled particles, where the state of the particles is given by their moving direction (left or right), which is encoded by a spin-like variable, and their position. Particles interact by short-ranged, spring-like attractive forces and do not possess spin-spin interactions (i.e. velocity alignment). Newton's third law is broken in this model by assuming an asymmetric interaction range that is larger in the direction of the moving direction of the particle. We show that in this nonequilibrium system, due to the absence of the action-reaction symmetry, there exists an intimate link between phase separation and the formation of highly-coherent, spatially localized, moving flocks (i.e. collective motion). More specifically, we prove the existence of two fundamentally different types of active phase separation, which we refer to as neutral (NPS) and polar (PPS) phase separation. Furthermore, we indicate that NPS is subdivided in two classes with distinct critical exponents. These results are of key importance to understand that in Active Matter there exist several phase-separation classes and that the emergence of polar, self-organized patterns (i.e. flocks) does not require the presence of a velocity alignment.

show abstract

“…1 b right). In terms of symmetry, this is similar to the chasing interaction assumed in the escape-and-pursuit and cognitive flocking models [ 33 – 36 ], and can induce, e.g., chain migration. Indeed, our previous work [ 14 ] reported the rotating rings and spirals and dynamic assemblies with snake-like stripe shapes due to this CF term.…”

Section: Modelmentioning

confidence: 83%

Dynamic self-organization of migrating cells under constraints by spatial confinement and epithelial integrity

Hiraiwa

2022

Eur. Phys. J. E

View full text Add to dashboard Cite

Understanding how migrating cells can establish both dynamic structures and coherent dynamics may provide mechanistic insights to study how living systems acquire complex structures and functions. Recent studies revealed that intercellular contact communication plays a crucial role for establishing cellular dynamic self-organization (DSO) and provided a theoretical model of DSO for migrating solitary cells in a free space. However, to apply those understanding to situations in living organisms, we need to know the role of cell–cell communication for tissue dynamics under spatial confinements and epithelial integrity. Here, we expand the previous numerical studies on DSO to migrating cells subjected spatial confinement and/or epithelial integrity. An epithelial monolayer is simulated by combining the model of cellular DSO and the cellular vertex model in two dimensions for apical integrity. Under confinement to a small space, theoretical models of both solitary and epithelial cells exhibit characteristic coherent dynamics, including apparent swirling. We also find that such coherent dynamics can allow the cells to overcome the strong constraint due to spatial confinement and epithelial integrity. Furthermore, we demonstrate how epithelial cell clusters behave without spatial confinement and find various cluster dynamics, including spinning, migration and elongation. Graphical abstract

show abstract

Hydrodynamic Equations for Flocking Models without Velocity Alignment

Cited by 12 publications

References 46 publications

Gliding filament system giving both global orientational order and clusters in collective motion

Gliding filament system giving both global orientational order and clusters in collective motion

Phase separation and emergence of collective motion in a one-dimensional system of active particles

Dynamic self-organization of migrating cells under constraints by spatial confinement and epithelial integrity

Contact Info

Product

Resources

About