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On the inf-sup condition for higher order mixed FEM on meshes with hanging nodes

Vincent Heuveline, Friedhelm Schieweck (2007)

ESAIM: Mathematical Modelling and Numerical Analysis

We consider higher order mixed finite element methods for the incompressible Stokes or Navier-Stokes equations with Qr-elements for the velocity and discontinuous P r - 1 -elements for the pressure where the order r can vary from element to element between 2 and a fixed bound r * . We prove the inf-sup condition uniformly with respect to the meshwidth h on general quadrilateral and hexahedral meshes with hanging nodes.

On the inhomogeneous nonlinear Schrödinger equation with harmonic potential and unbounded coefficient

Jianqing Chen (2010)

Czechoslovak Mathematical Journal

By deriving a variant of interpolation inequality, we obtain a sharp criterion for global existence and blow-up of solutions to the inhomogeneous nonlinear Schrödinger equation with harmonic potential i ϕ t = - ϕ + | x | 2 ϕ - | x | b | ϕ | p - 2 ϕ . We also prove the existence of unstable standing-wave solutions via blow-up under certain conditions on the unbounded inhomogeneity and the power of nonlinearity, as well as the frequency of the wave.

On the instantaneous spreading for the Navier–Stokes system in the whole space

Lorenzo Brandolese, Yves Meyer (2002)

ESAIM: Control, Optimisation and Calculus of Variations

We consider the spatial behavior of the velocity field u ( x , t ) of a fluid filling the whole space n ( n 2 ) for arbitrarily small values of the time variable. We improve previous results on the spatial spreading by deducing the necessary conditions u h ( x , t ) u k ( x , t ) d x = c ( t ) δ h , k under more general assumptions on the localization of u . We also give some new examples of solutions which have a stronger spatial localization than in the generic case.

On the Instantaneous Spreading for the Navier–Stokes System in the Whole Space

Lorenzo Brandolese, Yves Meyer (2010)

ESAIM: Control, Optimisation and Calculus of Variations

We consider the spatial behavior of the velocity field u(x, t) of a fluid filling the whole space n ( n 2 ) for arbitrarily small values of the time variable. We improve previous results on the spatial spreading by deducing the necessary conditions u h ( x , t ) u k ( x , t ) d x = c ( t ) δ h , k under more general assumptions on the localization of u. We also give some new examples of solutions which have a stronger spatial localization than in the generic case.

On the integral representation of superbiharmonic functions

Ali Abkar (2007)

Czechoslovak Mathematical Journal

We consider a nonnegative superbiharmonic function w satisfying some growth condition near the boundary of the unit disk in the complex plane. We shall find an integral representation formula for w in terms of the biharmonic Green function and a multiple of the Poisson kernel. This generalizes a Riesz-type formula already found by the author for superbihamonic functions w satisfying the condition 0 w ( z ) C ( 1 - | z | ) in the unit disk. As an application we shall see that the polynomials are dense in weighted Bergman...

On the interior boundary-value problem for the stationary Povzner equation with hard and soft interactions

Vladislav A. Panferov (2004)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze

The Povzner equation is a version of the nonlinear Boltzmann equation, in which the collision operator is mollified in the space variable. The existence of stationary solutions in L 1 is established for a class of stationary boundary-value problems in bounded domains with smooth boundaries, without convexity assumptions. The results are obtained for a general type of collision kernels with angular cutoff. Boundary conditions of the diffuse reflection type, as well as the given incoming profile, are...

Currently displaying 1361 – 1380 of 2162