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Related papers: Defects in active nematics: algorithms for identif…

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Topological defects are at the root of the large-scale organization of liquid crystals. In two-dimensional active nematics, two classes of topological defects of charges $\pm 1/2$ are known to play a major role due to active stresses.…

Soft Condensed Matter · Physics 2022-04-08 Louis Brézin , Thomas Risler , Jean-François Joanny

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

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

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 investigate similarities in the micro-structural dynamics between externally driven and actively driven nematics. Walls, lines of strong deformations in the director field, and topological defects are characteristic features of an active…

Soft Condensed Matter · Physics 2015-04-28 Sumesh P. Thampi , Ramin Golestanian , Julia M. Yeomans

We derive and numerically solve a surface active nematodynamics model. We validate the numerical approach on a sphere and analyse the influence of hydrodynamics on the oscillatory motion of topological defects. For ellipsoidal surfaces the…

Soft Condensed Matter · Physics 2022-09-07 Michael Nestler , Axel Voigt

We study the spatiotemporal patterns that emerge when an active nematic film is topologically constraint. These topological constraints allow to control the non-equilibrium dynamics of the active system. We consider ellipsoidal shapes for…

Soft Condensed Matter · Physics 2017-03-13 Francesco Alaimo , Christian Köhler , Axel Voigt

We investigate the dynamics of active nematic liquid crystals on deformable membranes, focusing on the interplay between active stress and anisotropic curvature coupling. Using a minimal model, we simulate the coupled evolution of the…

Soft Condensed Matter · Physics 2026-05-19 Yuki Hirota , Nariya Uchida

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 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

Topology transcends boundaries that conventionally delineate physical, biological and engineering sciences. Our ability to mathematically describe topology, combined with our access to precision tracking and manipulation approaches, has…

Biological Physics · Physics 2021-01-01 Anupam Sengupta

Active materials are capable of converting free energy into directional motion, giving rise to striking dynamical phenomena. Developing a general understanding of their structure in relation to the underlying non-equilibrium physics would…

Soft Condensed Matter · Physics 2018-10-17 Nitin Kumar , Rui Zhang , Juan J. de Pablo , Margaret L. Gardel

Using agent-based simulations of self-propelled particles subject to short-range repulsion and nematic alignment we explore the dynamical phases of a dense active material confined to the surface of a sphere. We map the dynamical phase…

Soft Condensed Matter · Physics 2018-04-25 Silke Henkes , M. Cristina Marchetti , Rastko Sknepnek

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

Non-equilibrium dynamics of topological defects can be used as a fundamental propulsion mechanism in microscopic active matter. Here, we demonstrate swimming of topological defect-propelled colloidal particles in (passive) nematic fluids…

Soft Condensed Matter · Physics 2021-09-30 Tianyi Yao , Žiga Kos , Yimin Luo , Edward B. Steager , Miha Ravnik , Kathleen J. Stebe

Recent experimental observations have suggested that topological defects can facilitate the creation of sharp features in developing embryos. Whereas these observations echo established knowledge about the interplay between geometry and…

Soft Condensed Matter · Physics 2023-07-25 Ludwig A. Hoffmann , Livio Nicola Carenza , Luca Giomi

We describe the flows and morphological dynamics of topological defect lines and loops in three-dimensional active nematics and show, using theory and numerical modelling, that they are governed by the local profile of the orientational…

Soft Condensed Matter · Physics 2020-03-13 Jack Binysh , Žiga Kos , Simon Čopar , Miha Ravnik , Gareth P. Alexander

Active matter encompasses different nonequilibrium systems in which individual constituents convert energy into non-conservative forces or motion at the microscale. This review provides an elementary introduction to the role of topology in…

Soft Condensed Matter · Physics 2022-06-28 Suraj Shankar , Anton Souslov , Mark J. Bowick , M. Cristina Marchetti , Vincenzo Vitelli

There is now growing evidence of the emergence and biological functionality of liquid crystal features, including nematic order and topological defects, in cellular tissues. However, how such features that intrinsically rely on particle…

Soft Condensed Matter · Physics 2019-02-06 Romain Mueller , Julia Yeomans , Amin Doostmohammadi

We use topological data analysis as a tool to analyze the fit of mathematical models to experimental data. This study is built on data obtained from motion tracking groups of aphids in [Nilsen et al., PLOS One, 2013] and two random walk…

Quantitative Methods · Quantitative Biology 2018-11-13 M. Ulmer , Lori Ziegelmeier , Chad M. Topaz