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Related papers: Dynamical arrest in active nematic turbulence

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The self-propulsion of +1/2 topological defects is a hallmark of active nematic fluids, where the defects are advected by the flow field they themselves generate. In this paper we propose a minimal model for defect self-propulsion in a…

Soft Condensed Matter · Physics 2025-08-08 Fridtjof Brauns , Myles O'Leary , Arthur Hernandez , Mark J. Bowick , M. Cristina Marchetti

We numerically model a two-dimensional active nematic confined by a periodic array of fixed obstacles. Even in the passive nematic, the appearance of topological defects is unavoidable due to planar anchoring by the obstacle surfaces. We…

Soft Condensed Matter · Physics 2024-01-25 Cody D. Schimming , C. J. O. Reichhardt , C. Reichhardt

Topological defects are distinctive signatures of liquid crystals. They profoundly affect the viscoelastic behavior of the fluid by constraining the orientational structure in a way that inevitably requires global changes not achievable…

Soft Condensed Matter · Physics 2015-06-19 Luca Giomi , Mark J. Bowick , Prashant Mishra , Rastko Sknepnek , M. Cristina Marchetti

Active materials are those in which individual, uncoordinated local stresses drive the material out of equilibrium on a global scale. Examples of such assemblies can be seen across scales from schools of fish to the cellular cytoskeleton…

Soft Condensed Matter · Physics 2022-09-30 Nitin Kumar , Rui Zhang , Steven A. Redford , Juan J. de Pablo , Margaret L. Gardel

We investigate the turbulent dynamics of a two-dimensional active nematic liquid crystal con- strained on a curved surface. Using a combination of hydrodynamic and particle-based simulations, we demonstrate that the fundamental structural…

Soft Condensed Matter · Physics 2019-05-01 D. J. G. Pearce , Perry W. Ellis , Alberto Fernandez-Nieves , L. Giomi

Defect dynamics in a thin active nematic layer is studied by asymptotic matching of solutions in the defect core and the far field. The analysis is facilitated by the correspondence between the 2D nematic and complex scalar field models.…

Soft Condensed Matter · Physics 2015-06-16 L. M. Pismen

Coherent flows of self-propelled particles are characterized by vortices and jets that sustain chaotic flows, referred to as active turbulence. Here, we reveal a crossover between defect-free active turbulence and active turbulence laden…

Soft Condensed Matter · Physics 2023-05-26 Benjamin H. Andersen , Julian Renaud , Jonas Rønning , Luiza Angheluta , Amin Doostmohammadi

The persistent dynamics in systems out of equilibrium, particularly those characterized by annihilation and creation of topological defects, is known to involve complicated spatiotemporal processes and is deemed difficult to control. Here…

Soft Condensed Matter · Physics 2022-11-22 Zhi-Feng Huang , Hartmut Löwen , Axel Voigt

We describe a numerical investigation of a continuum model of an active nematic, concentrating on the regime of active turbulence. Results are presented for the effect of three parameters, activity, elastic constant and rotational diffusion…

Soft Condensed Matter · Physics 2015-06-18 Sumesh P. Thampi , Ramin Golestanian , Julia M. Yeomans

Active nematic fluids confined in narrow channels generate spontaneous flows when the activity is sufficiently intense. Recently, it was shown that if the molecular anchoring at the channel walls is conflicting flows are initiated even in…

Soft Condensed Matter · Physics 2021-11-02 C. Rorai , F. Toschi , I. Pagonabarraga

Collectively moving cellular systems often contain a proportion of dead cells or non-motile genotypes. When mixed, nematically aligning motile and non-motile agents are known to segregate spontaneously. However, the role that topological…

We establish how active stress globally affects the morphology of disclination lines of a three dimensional active nematic liquid crystal under chaotic flow. Thanks to a defect detection algorithm based on the local nematic orientation, we…

Soft Condensed Matter · Physics 2025-06-30 Pasquale Digregorio , Cecilia Rorai , Ignacio Pagonabarraga , Federico Toschi

The problem of low Reynolds number turbulence in active nematic fluids is theoretically addressed. Using numerical simulations I demonstrate that an incompressible turbulent flow, in two-dimensional active nematics, consists of an ensemble…

Soft Condensed Matter · Physics 2015-08-04 Luca Giomi

Active fluids, such as cytoskeletal filaments, bacterial colonies and epithelial cell layers, exhibit distinctive orientational coherence, often characterized by nematic order and topological defects. By contrast, little is known about…

Soft Condensed Matter · Physics 2021-04-07 Mattia Serra , Linnea Lemma , Luca Giomi , Zvonimir Dogic , L. Mahadevan

We consider a phenomenological continuum theory for an extensile, overdamped active nematic liquid crystal, applicable in the dense regime. Constructed from general principles, the theory is universal, with parameters independent of any…

Soft Condensed Matter · Physics 2015-06-12 Elias Putzig , Gabriel S. Redner , Arvind Baskaran , Aparna Baskaran

We numerically investigate the effect of a periodic array of asymmetric obstacles in a two-dimensional active nematic. We find that activity in conjunction with the asymmetry leads to a ratchet effect or unidirectional flow of the fluid…

Soft Condensed Matter · Physics 2024-03-25 Cody D. Schimming , C. J. O. Reichhardt , C. Reichhardt

We study two models of overdamped self-propelled disks in two dimensions, with and without aligning interactions. Active mesoscale flows leading to chaotic advection emerge in both models in the homogeneous dense fluid away from dynamical…

Soft Condensed Matter · Physics 2024-06-07 Yann-Edwin Keta , Juliane Klamser , Robert L. Jack , Ludovic Berthier

The topological properties of many materials are central to their behavior, with the dynamics of topological defects being particularly important to intrinsically out-of-equilibrium, active materials. In this paper, local manipulation of…

Soft Condensed Matter · Physics 2019-11-01 David P. Rivas , Tyler N. Shendruk , Robert R. Henry , Daniel H. Reich , Robert L. Leheny

Confining a liquid crystal imposes topological constraints on the orientational order, allowing global control of equilibrium systems by manipulation of anchoring boundary conditions. In this article, we investigate whether a similar…

In many active systems, swimmers collectively stir the surrounding fluid to stabilize some self-sustained vortices. The resulting nonequilibrium state is often referred to as active turbulence, by analogy with the turbulence of passive…

Statistical Mechanics · Physics 2026-03-03 Byjesh N. Radhakrishnan , Francesco Serafin , Thomas L. Schmidt , Étienne Fodor