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A note on a discrete form of Friedrichs' inequality

Libor Čermák (1983)

Aplikace matematiky

The proof of the Friedrichs' inequality on the class of finite dimensional spaces used in the finite element method is given. In particular, the approximate spaces generated by simplicial isoparametric elements are considered.

A Note on an Application of the Lasota-York Fixed Point Theorem in the Turbulent Transport Problem

Tomasz Komorowski, Grzegorz Krupa (2004)

Bulletin of the Polish Academy of Sciences. Mathematics

We study a model of motion of a passive tracer particle in a turbulent flow that is strongly mixing in time variable. In [8] we have shown that there exists a probability measure equivalent to the underlying physical probability under which the quasi-Lagrangian velocity process, i.e. the velocity of the flow observed from the vintage point of the moving particle, is stationary and ergodic. As a consequence, we proved the existence of the mean of the quasi-Lagrangian velocity, the so-called Stokes...

A note on bounds for non-linear multivalued homogenized operators

Nils Svanstedt (1998)

Applications of Mathematics

In this paper we study the behaviour of maximal monotone multivalued highly oscillatory operators. We construct Reuss-Voigt-Wiener and Hashin-Shtrikmann type bounds for the minimal sections of G-limits of multivalued operators by using variational convergence and convex analysis.

A note on critical times of 2 × 2 quasilinear hyperbolic systems

Ivan Straškraba (1984)

Aplikace matematiky

In this paper the exact formula for the critical time of generating discontinuity (shock wave) in a solution of a 2 × 2 quasilinear hyperbolic system is derived. The applicability of the formula in the engineering praxis is shown on one-dimensional equations of isentropic non-viscous compressible fluid flow.

A Note on Div-Curl Lemma

Gala, Sadek (2007)

Serdica Mathematical Journal

2000 Mathematics Subject Classification: 42B30, 46E35, 35B65.We prove two results concerning the div-curl lemma without assuming any sort of exact cancellation, namely the divergence and curl need not be zero, and d i v ( u v ) H 1 ( R d ) which include as a particular case, the result of [3].

A note on lifting of Carnot groups.

Andrea Bonfiglioli, Francesco Uguzzoni (2005)

Revista Matemática Iberoamericana

We prove that every homogeneous Carnot group can be lifted to a free homogeneous Carnot group. Though following the ideas of Rothschild and Stein, we give simple and self-contained arguments, providing a constructive proof, as shown in the examples.

A note on maximal estimates for stochastic convolutions

Mark Veraar, Lutz Weis (2011)

Czechoslovak Mathematical Journal

In stochastic partial differential equations it is important to have pathwise regularity properties of stochastic convolutions. In this note we present a new sufficient condition for the pathwise continuity of stochastic convolutions in Banach spaces.

A note on measure-valued solutions to the full Euler system

Václav Mácha, Emil Wiedemann (2022)

Applications of Mathematics

We construct two particular solutions of the full Euler system which emanate from the same initial data. Our aim is to show that the convex combination of these two solutions form a measure-valued solution which may not be approximated by a sequence of weak solutions. As a result, the weak* closure of the set of all weak solutions, considered as parametrized measures, is not equal to the space of all measure-valued solutions. This is in stark contrast with the incompressible Euler equations.

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