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Related papers: Lower Bounds for Advection-Diffusion Equations: An…

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We establish a novel convergent iteration framework for a weak approximation of general switching diffusion. The key theoretical basis of the proposed approach is a restriction of the maximum number of switching so as to untangle and…

Numerical Analysis · Mathematics 2023-07-06 Qinjing Qiu , Reiichiro Kawai

We prove new bounds on the number of incidences between points and higher degree algebraic curves. The key ingredient is an improved initial bound, which is valid for all fields. Then we apply the polynomial method to obtain global bounds…

Combinatorics · Mathematics 2015-03-31 Hong Wang , Ben Yang , Ruixiang Zhang

In theory, diffusion curves promise complex color gradations for infinite-resolution vector graphics. In practice, existing realizations suffer from poor scaling, discretization artifacts, or insufficient support for rich boundary…

Numerical Analysis · Mathematics 2023-11-27 Seungbae Bang , Kirill Serkh , Oded Stein , Alec Jacobson

The analytical solution of the equation describing diffusion of intrinsic point defects has been obtained for a one-dimensional finite-length domain. This solution is intended for investigating and modeling the changes in defect…

Materials Science · Physics 2014-06-26 O. I. Velichko

Consider the steady neutron transport equation in 2D convex domains with in-flow boundary condition. In this paper, we establish the diffusive limit while the boundary layers are present. Our contribution relies on a delicate decomposition…

Analysis of PDEs · Mathematics 2020-01-08 Lei Wu

We model the evolution of the concentration field of macromolecules in a symmetric field-flow fractionation (FFF) channel by a one-dimensional advection-diffusion equation. The coefficients are precisely determined from the fluid dynamics.…

chao-dyn · Physics 2007-05-23 S. A. Suslov , A. J. Roberts

Standard and anomalous transport in incompressible flow is investigated using multiscale techniques. Eddy-diffusivities emerge from the multiscale analysis through the solution of an auxiliary equation. From the latter it is derived an…

Condensed Matter · Physics 2009-10-22 L. Biferale , A. Crisanti , M. Vergassola , A. Vulpiani

We provide an unconditional $L^2$ upper bound for the boundary layer separation of Leray-Hopf solutions in a smooth bounded domain. By layer separation, we mean the discrepancy between a (turbulent) low-viscosity Leray-Hopf solution $u^\nu$…

Analysis of PDEs · Mathematics 2024-04-29 Alexis F. Vasseur , Jincheng Yang

We show short-time existence for curves driven by curve diffusion flow with a prescribed contact angle $\alpha \in (0, \pi)$: The evolving curve has free boundary points, which are supported on a line and it satisfies a no-flux condition.…

Analysis of PDEs · Mathematics 2018-12-03 Helmut Abels , Julia Butz

We study the free boundary regularity of the traveling wave solutions to a degenerate advection-diffusion problem of Porous Medium type, whose existence was proved in \cite{MonsaingonNovikovRoquejoffre}. We set up a finite difference scheme…

Analysis of PDEs · Mathematics 2018-11-02 Léonard Monsaingeon

We introduce a new wave formulation for the relativistic Euler equations with vacuum boundary conditions that consists of a system of non-linear wave equations in divergence form with a combination of acoustic and Dirichlet boundary…

General Relativity and Quantum Cosmology · Physics 2019-07-23 Todd A. Oliynyk

In this work, we obtain decay bounds for a class of ID dispersive equations that includes the linearized water wave. These decay bounds display a surprising growth factor, which we show is sharp, The proofs rely on careful analysis of…

Analysis of PDEs · Mathematics 2014-11-13 Jennifer Beichman

This study is concerned with the diffusion of a passive scalar $\Theta(\r,t)$ advected by general $n$-dimensional shear flows $\u=u(y,z,...,t)\hat{x}$ having finite mean-square velocity gradients. The unidirectionality of the incompressible…

Fluid Dynamics · Physics 2009-11-13 Chuong V. Tran

Simple modifications for higher-order Godunov-type difference schemes are presented which allow for accurate advection of multi-fluid flows in hydrodynamic simulations. The constraint that the sum of all mass fractions has to be equal to…

Astrophysics · Physics 2009-09-25 Tomasz Plewa , Ewald Mueller

We consider pressure-driven flows in wide microchannels, and discuss how a transverse shear, generated by misaligned superhydrophobic walls, impacts cross-sectional spreading of Brownian particles. We show that such a transverse shear can…

Fluid Dynamics · Physics 2017-09-27 Tatiana V. Nizkaya , Evgeny S. Asmolov , Olga I. Vinogradova

We give a new algorithm for learning mixtures of $k$ Gaussians (with identity covariance in $\mathbb{R}^n$) to TV error $\varepsilon$, with quasi-polynomial ($O(n^{\text{poly\,log}\left(\frac{n+k}{\varepsilon}\right)})$) time and sample…

Machine Learning · Computer Science 2025-03-05 Khashayar Gatmiry , Jonathan Kelner , Holden Lee

Denoising diffusions are a powerful method to generate approximate samples from high-dimensional data distributions. Recent results provide polynomial bounds on their convergence rate, assuming $L^2$-accurate scores. Until now, the tightest…

Machine Learning · Statistics 2024-03-07 Joe Benton , Valentin De Bortoli , Arnaud Doucet , George Deligiannidis

Many physical systems of interest involve the close interaction of a flow in a domain with complex, time-varying boundaries. Treatment of boundaries of this nature is cumbersome due to the difficulty in explicitly tracking boundaries that…

Fluid Dynamics · Physics 2025-02-25 Emma M. Boyd , Eric Sandall , Maycon Meier , J. Matt Quinlan , Brandon Runnels

In this paper we study the asymptotic behavior of a very fast diffusion PDE in 1D with periodic boundary conditions. This equation is motivated by the gradient flow approach to the problem of quantization of measures introduced in…

Analysis of PDEs · Mathematics 2016-02-29 Mikaela Iacobelli

The low Mach limit for 1D non-isentropic compressible Navier-Stokes flow, whose density and temperature have different asymptotic states at infinity, is rigorously justified. The problems are considered on both well-prepared and…

Analysis of PDEs · Mathematics 2016-10-28 Feimin Huang , Tian-Yi Wang , Yong Wang