Displaying 821 – 840 of 1688

Showing per page

Some remarks on the Weyl asymptotics by the approximate spectral projection method

Ernesto Buzano (2000)

Bollettino dell'Unione Matematica Italiana

In questo lavoro studiamo il resto relativo della formula asintotica per gli autovalori di un operatore differenziale in R n , ottenuta mediante il metodo delle proiezioni spettrali approssimate ([3], Theorem 6.2). In un primo tempo diamo un controesempio di un operatore di Schrödinger con potenziale a crescita algebrica, per il quale il resto non è limitato. Quindi specifichiamo alcune condizioni addizionali da imporre all'operatore in modo da avere un resto infinitesimo.

Some remarks on two-scale convergence and periodic unfolding

Jan Franců, Nils E M Svanstedt (2012)

Applications of Mathematics

The paper discusses some aspects of the adjoint definition of two-scale convergence based on periodic unfolding. As is known this approach removes problems concerning choice of the appropriate space for admissible test functions. The paper proposes a modified unfolding which conserves integral of the unfolded function and hence simplifies the proofs and its application in homogenization theory. The article provides also a self-contained introduction to two-scale convergence and gives ideas for generalization...

Some remarks to the compactness of steady compressible isentropic Navier-Stokes equations via the decomposition method

Antonín Novotný (1996)

Commentationes Mathematicae Universitatis Carolinae

In [18]–[19], P.L. Lions studied (among others) the compactness and regularity of weak solutions to steady compressible Navier-Stokes equations in the isentropic regime with arbitrary large external data, in particular, in bounded domains. Here we investigate the same problem, combining his ideas with the method of decomposition proposed by Padula and myself in [29]. We find the compactness of the incompressible part u of the velocity field v and we give a new proof of the compactness of the “effective...

Some results about dissipativity of Kolmogorov operators

Giuseppe Da Prato, Luciano Tubaro (2001)

Czechoslovak Mathematical Journal

Given a Hilbert space H with a Borel probability measure ν , we prove the m -dissipativity in L 1 ( H , ν ) of a Kolmogorov operator K that is a perturbation, not necessarily of gradient type, of an Ornstein-Uhlenbeck operator.

Some results on critical groups for a class of functionals defined on Sobolev Banach spaces

Silvia Cingolani, Giuseppina Vannella (2001)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

We present critical groups estimates for a functional f defined on the Banach space W 0 1 , p Ω , Ω bounded domain in R N , 2 < p < , associated to a quasilinear elliptic equation involving p -laplacian. In spite of the lack of an Hilbert structure and of Fredholm property of the second order differential of f in each critical point, we compute the critical groups of f in each isolated critical point via Morse index.

Some results on invariant measures in hydrodynamics

B. Ferrario (2000)

Bollettino dell'Unione Matematica Italiana

In questa nota, si presentano risultati di esistenza e di unicità di misure invarianti per l'equazione di Navier-Stokes che governa il moto di un fluido viscoso incomprimibile omogeneo in un dominio bidimensionale soggetto a una forzante che ha due componenti: una deterministica e una di tipo rumore bianco nella variabile temporale.

Some results on semilinear systems on the unbounded space R3.

J. M. Mercier (2000)

Revista Matemática Complutense

We study in this paper some systems, using standard tools devoted to the analysis of semilinear elliptic problems on R3. These systems do not admit any non trivial radial solutions in the E1 E2 = + 1 cases. A first type of solution consists in a ground state of R (-1,-1), exhibited by variational arguments, whose structure is a finite energy perturbation of a non trivial constant solution of R (-1,-1). A second type consists in a radial, oscillating, asymptotically null at infinity solution in the...

Some results on strongly nonlinear anisotropic differential equations

L. Bougoffa, A. El Khalil, S. El Manouni (2010)

Applicationes Mathematicae

The paper concerns the existence of weak solutions to nonlinear elliptic equations of the form A(u) + g(x,u,∇u) = f, where A is an operator from an appropriate anisotropic function space to its dual and the right hand side term is in L 1 + m with 0 < m < 1. We assume a sign condition on the nonlinear term g, but no growth restrictions on u.

Currently displaying 821 – 840 of 1688