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Related papers: Dynamic Scaling of Two-Dimensional Polar Flocks

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We study the hydrodynamic behavior of three dimensional (3D) incompressible collections of self-propelled entities in contact with a momentum sink in a state with non-zero average velocity, hereafter called 3D easy-plane incompressible…

Soft Condensed Matter · Physics 2018-10-31 Leiming Chen , Chiu Fan Lee , John Toner

We propose a ballistic coalescence model (punctuated-Hamiltonian approach) mimicking the fusion of vortices in freely decaying two-dimensional turbulence. A temporal scaling behaviour is reached where the vortex density evolves like…

Statistical Mechanics · Physics 2009-10-31 Emmanuel Trizac

A kinetic-fluid model describing the evolutions of disperse two-phase flows is considered. The model consists of the Vlasov-Fokker-Planck equation for the particles (disperse phase) coupled with the compressible Navier-Stokes equations for…

Analysis of PDEs · Mathematics 2017-04-06 Fucai Li , Yanmin Mu , Dehua Wang

A novel formulation of second-order relativistic viscous fluid dynamics based on the effective Boltzmann equation for quasi-particles with medium-dependent masses is briefly reviewed.~The evolution equations for the shear and bulk…

Nuclear Theory · Physics 2017-08-07 Radoslaw Ryblewski

We introduce a class of lattice gas models of active matter systems whose hydrodynamic description can be derived exactly. We illustrate our approach by considering two systems exhibiting two of the most studied collective behaviours in…

Statistical Mechanics · Physics 2018-07-04 Mourtaza Kourbane-Houssene , Clément Erignoux , Thierry Bodineau , Julien Tailleur

We study the dynamic of polaritons in the Keldysh functional formalism. Dissipation is considered through the coupling of the exciton and photon fields to two independent photonic and excitonic baths. As such, this theory allows to describe…

Quantum Gases · Physics 2016-10-24 A. Rahmani , M. A. Sadeghzadeh

We study a two-dimensional incoherently pumped exciton-polariton condensate described by an open-dissipative Gross-Pitaevskii equation for the polariton dynamics coupled to a rate equation for the exciton density. Adopting a hydrodynamic…

We introduce a closure model for coarse-grained kinetic theories of polar active fluids. Based on a quasi-equilibrium approximation of the particle distribution function, the model closely captures important analytical properties of the…

Soft Condensed Matter · Physics 2022-06-17 Scott Weady , David B. Stein , Michael J. Shelley

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 derive the equations of motion for a planar rigid body of circular shape moving in a 2D perfect fluid with point vortices using symplectic reduction by stages. After formulating the theory as a mechanical system on a configuration space…

Dynamical Systems · Mathematics 2009-07-22 Joris Vankerschaver , Eva Kanso , Jerrold E. Marsden

We propose a non-equilibrium continuum dynamical model for the collective motion of large groups of biological organisms (e.g., flocks of birds, slime molds, etc.) Our model becomes highly non-trivial, and different from the equilibrium…

adap-org · Physics 2015-06-30 Yuhai Tu , John Toner

We introduce a model for self-organized dynamics which, we argue, addresses several drawbacks of the celebrated Cucker-Smale (C-S) model. The proposed model does not only take into account the distance between agents, but instead, the…

Analysis of PDEs · Mathematics 2015-05-27 Sebastien Motsch , Eitan Tadmor

Holographic duality provides a description of strongly coupled quantum systems in terms of weakly coupled gravitational theories in a higher-dimensional space. It is a challenge, however, to quantitatively determine the physical parameters…

High Energy Physics - Theory · Physics 2021-09-08 Paul Wittmer , Christian-Marcel Schmied , Thomas Gasenzer , Carlo Ewerz

We devise an iterative scheme for numerically calculating dynamical two-point correlation functions in integrable many-body systems, in the Eulerian scaling limit. Expressions for these were originally derived in Ref. [1] by combining the…

Statistical Mechanics · Physics 2021-01-01 Frederik S. Møller , Gabriele Perfetto , Benjamin Doyon , Jörg Schmiedmayer

(abridged) We present a detailed derivation of a simple hydrodynamic two-fluid model, which aims at the description of the phase separation of non-entangled polymer solutions, where viscoelastic effects play a role. It is directly based…

Spontaneously flowing liquids have been successfully engineered from a variety of biological and synthetic self-propelled units. Together with their orientational order, wave propagation in such active fluids have remained a subject of…

Soft Condensed Matter · Physics 2018-10-10 Delphine Geyer , Alexandre Morin , Denis Bartolo

Collective dynamics can be observed among many animal species, and have given rise in the last decades to an active and interdisciplinary field of study. Such behaviors are often modeled by active matter, in which each individual is…

Mathematical Physics · Physics 2021-08-31 Clément Erignoux

We introduce a stochastic agent-based model for the flocking dynamics of self-propelled particles that exhibit velocity-alignment interactions with neighbours within their field of view. The stochasticity in the dynamics of the model arises…

Statistical Mechanics · Physics 2019-07-24 Trilochan Bagarti , Shakti N. Menon

We briefly review a recently proposed formalism of perfect-fluid hydrodynamics with spin, which is a generalization of the standard hydrodynamic framework and provides a natural tool for describing the evolution of spin-polarized systems of…

High Energy Physics - Phenomenology · Physics 2020-11-05 Rajeev Singh

We study the one-dimensional active Ising model in which aligning particles undergo diffusion biased by the signs of their spins. The phase diagram obtained varying the density of particles, their hopping rate and the temperature…

Statistical Mechanics · Physics 2024-10-17 Brieuc Benvegnen , Hugues Chaté , Pavel Krapivsky , Julien Tailleur , Alexandre Solon