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In this paper we construct a large class of new normal forms for Levi-nondegenerate real hypersurfaces in complex spaces. We adopt a general approach illustrating why these normal forms are natural and which role is played by the celebrated…

Complex Variables · Mathematics 2015-02-16 Dmitri Zaitsev

We study Schur-type upper triangular forms for elements, T, of von Neumann algebras equipped with faithful, normal, tracial states. These were introduced in a paper of Dykema, Sukochev and Zanin; they are based on Haagerup-Schultz…

Operator Algebras · Mathematics 2017-10-17 Ken Dykema , Joseph Noles , Dmitriy Zanin

We present an exact analytic solution for decaying incompressible magnetohydrodynamic (MHD) turbulence. Our solution reveals a dual formulation in terms of two interacting Euler ensembles--one for hydrodynamic and another for magnetic…

Fluid Dynamics · Physics 2025-05-15 Alexander Migdal

Three-dimensional (3D) high-speed compressible flow is a typical nonlinear, nonequilibrium, and multiscale complex flow. Traditional fluid mechanics models, based on the quasi-continuum assumption and near-equilibrium approximation, are…

Fluid Dynamics · Physics 2025-04-14 Qinghong Guo , Yanbiao Gan , Bin Yang , Yanhong Wu , Huilin Lai , Aiguo Xu

The Schr\"odinger-Poisson formalism has found a number of applications in cosmology, particularly in describing the growth by gravitational instability of large-scale structure in a universe dominated by ultra-light scalar particles. Here…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-15 Peter Coles , Aoibhinn Gallagher

The formation and evolution of nonlinear and turbulent dynamical structures in two-dimensional complex plasmas and fluids is explored by means of generalised (drift) fluid simulations. Recent numerical results on turbulence in dusty…

Plasma Physics · Physics 2012-02-27 Alexander Kendl

The study is devoted to the development of new effective tools and methods of ana-lytical hydrodynamics, including problems of existence, smoothness and structure of laminar and turbulent flows. The main problem is complex Navier-Stokes…

Fluid Dynamics · Physics 2007-05-23 Anatoly N. Panchenkov

In this paper we study a coupled system modeling the movement of a deformable solid immersed in a fluid. For the solid we consider a given deformation that has to obey several physical constraints. The motion of the fluid is modeled by the…

Analysis of PDEs · Mathematics 2014-07-08 Sébastien Court

Based on the analysis of the velocity gradient tensor, we investigate in this paper the physical interpretation and limitations of four vortex criteria: $\omega$, $Q$, $\varDelta$ and $\lambda_{ci}$, and reveal the actual physical meaning…

Fluid Dynamics · Physics 2024-06-06 Zhen Li , Xiwen Zhang , Feng He

We derive a new formulation of the $3D$ compressible Euler equations with dynamic entropy exhibiting remarkable null structures and regularity properties. Our results hold for an arbitrary equation of state (which yields the pressure in…

Analysis of PDEs · Mathematics 2017-01-25 Jared Speck

Let A be a Q-linear pseudo-abelian rigid tensor category. A notion of finiteness due to Kimura and (independently) O'Sullivan guarantees that the ideal of numerically trivial endomorphism of an object is nilpotent. We generalize this result…

Algebraic Geometry · Mathematics 2011-05-02 Alessio Del Padrone , Carlo Mazza

By defining two important terms called basic perturbation vectors and obtaining their linear bounds, we obtain the linear componentwise perturbation bounds for unitary factors and upper triangular factors of the generalized Schur…

Numerical Analysis · Mathematics 2022-04-21 Guihua Zhang , Hanyu Li , Yimin Wei

We introduce a new heterogeneous multi-scale method for the simulation of flows of non-Newtonian fluids in general geometries and present its application to paradigmatic two-dimensional flows of polymeric fluids. Our method combines…

We establish the existence and uniqueness of smooth solutions with large vorticity and weak solutions with vortex sheets/entropy waves for the steady Euler equations for both compressible and incompressible fluids in arbitrary infinitely…

Analysis of PDEs · Mathematics 2019-02-19 Gui-Qiang G. Chen , Fei-Min Huang , Tian-Yi Wang , Wei Xiang

We develop a general formalism to describe the Renormalization Group Flow of Schur indices and fusion algebras of BPS line defects in four-dimensional ${\cal N}=2$ Supersymmetric Quantum Field Theories. The formalism includes and extends…

High Energy Physics - Theory · Physics 2025-03-24 Federico Ambrosino , Davide Gaiotto

The relation between the Toda lattices and similar nonlinear chains and orthogonal polynomials on the real line has been elaborated immensely for the last decades. We examine another system of the differential-difference equations known as…

Classical Analysis and ODEs · Mathematics 2015-06-26 L. Golinskii

Based on the characteristics of the multi-scale and similarity at different scales in turbulent flow, we propose a scale decomposition for solving the turbulence problem of incompressible Newtonian fluid. The solution domain is decomposed…

Fluid Dynamics · Physics 2023-02-21 Shanwen Tan

A vortex is intuitively recognized as the rotational/swirling motion of the fluids. However, an unambiguous and universally-accepted definition for vortex is yet to be achieved in the field of fluid mechanics, which is probably one of the…

Fluid Dynamics · Physics 2018-04-18 Chaoqun Liu , Yisheng Gao , Shuling Tian , Xiangrui Dong

We analyze the Vlasov equation coupled with the compressible Navier--Stokes equations with degenerate viscosities and vacuum. These two equations are coupled through the drag force which depends on the fluid density and the relative…

Analysis of PDEs · Mathematics 2021-08-20 Young-Pil Choi , Jinwook Jung

In the context of non overlapping domain decomposition methods, several algebraic approximations of the Dirichlet-to-Neumann (DtN) map are proposed in [F. X. Roux, et. al. Algebraic approximation of Dirichlet- to-Neumann maps for the…

Numerical Analysis · Mathematics 2011-05-10 Pawan Kumar