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Related papers: Hierarchical defect-induced condensation in active…

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To enhance the understanding of the behavior of active nematic, it is important to understand the behavior of topological defects. In this paper, we study the configuration of topological defects of a two-dimensional active nematic around a…

Soft Condensed Matter · Physics 2026-02-16 Hiroki Matsukiyo , Jun-ichi Fukuda

Topological defects, which are singular points in a director field, play a major role in shaping active systems. Here, we experimentally study topological defects and the flow patterns around them, that are formed during the highly rapid…

Soft Condensed Matter · Physics 2024-03-20 Victor Yashunsky , Daniel J. G. Pearce , Gil Ariel , Avraham Be'er

We study dry, dense active nematics at both particle and continuous levels. Specifically, extending the Boltzmann-Ginzburg-Landau approach, we derive well-behaved hydrodynamic equations from a Vicsek-style model with nematic alignment and…

Soft Condensed Matter · Physics 2019-12-20 Aurelio Patelli , Ilyas Djafer-Cherif , Igor S. Aranson , Eric Bertin , Hugues Chaté

We develop an approximate, analytical model for the velocity of defects in active nematics by combining recent results for the velocity of topological defects in nematic liquid crystals with the flow field generated from individual defects…

Soft Condensed Matter · Physics 2024-11-27 Cody D. Schimming , C. J. O. Reichhardt , C. Reichhardt

Engineering synthetic materials that mimic the remarkable complexity of living organisms is a fundamental challenge in science and technology. We study the spatiotemporal patterns that emerge when an active nematicfilm of microtubules and…

Topological defects are fundamental to the collective dynamics of non-equilibrium systems and in active matter, mediating spontaneous flows, dynamic self-organization, and emergent pattern formation. Here, we reveal critical states in…

We study the organization of topological defects in a system of nematogens confined to the two-dimensional sphere (S^2). We first perform Monte Carlo simulations of a fluid system of hard rods (spherocylinders) living in the tangent plane…

Soft Condensed Matter · Physics 2009-11-13 Homin Shin , Mark J. Bowick , Xiangjun Xing

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

Topological defects are ubiquitous on surfaces with orientational order fields. Here, we study equilibrium states generated by the feedback between geometry and nematic order on fluid membranes with an integer topological defect. When the…

Soft Condensed Matter · Physics 2024-11-14 D. J. G. Pearce , C. Thibault , Q. Chaboche , C. Blanch-Mercader

Topological defects in systems with liquid-crystalline order are crucial in determining their large-scale properties. In active systems, they are known to have properties impossible at equilibrium: for example, $+1/2$ defects in…

Soft Condensed Matter · Physics 2026-02-17 Giacomo Marco La Montagna , Sumeja Burekovic , Ananyo Maitra , Cesare Nardini

We report on the emergence of stable self-propelled bound defects in monolayers of active nematics, which form virtual full-integer topological defects in the form of vortices and asters. Through numerical simulations and analytical…

Soft Condensed Matter · Physics 2020-10-26 Kristian Thijssen , Amin Doostmohammadi

Inspired by recent experiments that highlight the role of nematic defects in the morphogenesis of epithelial tissues, we develop a minimal framework to study the dynamics of an active curved surface driven by its nematic texture. Allowing…

Soft Condensed Matter · Physics 2022-09-14 Farzan Vafa , 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

The growing interest in active nematics and the emerging evidence of the relevance of topological defects in biology asks for reliable data analysis tools to identify, classify and track such defects in simulation and microscopy data. We…

Soft Condensed Matter · Physics 2020-02-10 Dennis Wenzel , Michael Nestler , Sebastian Reuther , Maximilian Simon , Axel Voigt

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

Topological defects are increasingly being identified in various biological systems, where their characteristic flow fields and stress patterns are associated with continuous active stress generation by biological entities. Here, using…

Soft Condensed Matter · Physics 2022-11-09 Lasse Bonn , Aleksandra Ardaseva , Romain Mueller , Tyler N. Shendruk , Amin Doostmohammadi

We study how confinement transforms the chaotic dynamics of bulk microtubule-based active nematics into regular spatiotemporal patterns. For weak confinements, multiple continuously nucleating and annihilating topological defects…

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

Cell layers are often categorized as contractile or extensile active nematics but recent experiments on neural progenitor cells with induced $+1$ topological defects challenge this classification. In a bottom-up approach, we first study a…

Soft Condensed Matter · Physics 2024-09-13 Zihui Zhao , Yisong Yao , He Li , Yongfeng Zhao , Yujia Wang , Hepeng Zhang , Hugues Chat'e , Masaki Sano

Active matter is naturally out of equilibrium which results in the emergence of diverse dynamic steady states, including the omnipresent chaotic state known as the active turbulence. However, much less is known how active systems…

Soft Condensed Matter · Physics 2023-04-07 Nika Kralj , Miha Ravnik , Žiga Kos