EuDML | Browse

Let L be the distinguished Laplacian on certain semidirect products of ℝ by ℝⁿ which are of ax + b type. We prove pointwise estimates for the convolution kernels of spectrally localized wave operators of the form $e^{i t \sqrt L} ψ (\sqrt L / λ)$ for arbitrary time t and arbitrary λ > 0, where ψ is a smooth bump function supported in [-2,2] if λ ≤ 1 and in [1,2] if λ ≥ 1. As a corollary, we reprove a basic multiplier estimate of Hebisch and Steger [Math. Z. 245 (2003)] for this particular class of groups, and derive Sobolev...

Weakly semibounded boundary problems and sesquilinear forms

Gerd Grubb (1973)

Annales de l'institut Fourier

Let $A$ be a $2 m$ order differential operator in a hermitian vector bundle $E$ over a compact riemannian manifold $\overline{Ω}$ with boundary $Γ$ ; and denote by $A_{B}$ the realization defined by a normal differential boundary condition $B ρ u = 0$ ( $u \in H^{2 m} (E)$ , $ρ u =$ Cauchy data). We characterize, by an explicit condition on $A$ and $B$ near $Γ$ , the realizations $A_{B}$ for which there exists an integro-differential sesquilinear form $a_{B} (u, ν)$ on $H^{m} (E)$ such that $(A u, ν) = a_{B} (u, ν)$ on $D (A_{B})$ ; moreover we show that these are exactly the realizations satisfying a weak semiboundedness estimate:...

Weighted Miranda-Talenti inequality and applications to equations with discontinuous coefficients

Salvatore Leonardi (2002)

Commentationes Mathematicae Universitatis Carolinae

Let $Ω$ be an open bounded set in $ℝ^{n}$ $(n \geq 2)$ , with $C^{2}$ boundary, and $N^{p, λ} (Ω)$ ( $1 < p < + \infty$ , $0 \leq λ < n$ ) be a weighted Morrey space. In this note we prove a weighted version of the Miranda-Talenti...

Weighted Poincaré and Sobolev inequalites for vector fields satisfying Hörmander's condition and applications.

Guozhen Lu (1992)

Revista Matemática Iberoamericana

In this paper we mainly prove weighted Poincaré inequalities for vector fields satisfying Hörmander's condition. A crucial part here is that we are able to get a pointwise estimate for any function over any metric ball controlled by a fractional integral of certain maximal function. The Sobolev type inequalities are also derived. As applications of these weighted inequalities, we will show the local regularity of weak solutions for certain classes of strongly degenerate differential operators formed...

Well-posedness and regularity for a parabolic-hyperbolic Penrose-Fife phase field system

Elisabetta Rocca (2005)

Applications of Mathematics

This work is concerned with the study of an initial boundary value problem for a non-conserved phase field system arising from the Penrose-Fife approach to the kinetics of phase transitions. The system couples a nonlinear parabolic equation for the absolute temperature with a nonlinear hyperbolic equation for the phase variable $χ$ , which is characterized by the presence of an inertial term multiplied by a small positive coefficient $μ$ . This feature is the main consequence of supposing that the response...

Well-posedness in the Gevrey classes of the Cauchy problem for a non-strictly hyperbolic equation with coefficients depending on time

F. Colombini, E. Jannelli, S. Spagnolo (1983)

Annali della Scuola Normale Superiore di Pisa - Classe di Scienze

Currently displaying 741 – 760 of 920

Previous Page 38 Next

Displaying 741 – 760 of 920

[unknown]

[unknown]

Upper and lower bounds for a reactive-diffuse system with Arrhenius kinetics.

Valeurs propres de systèmes elliptiques définis sur des sous espaces

Variational and topological methods for operator equations involving duality mappings on Orlicz-Sobolev spaces.

Variational inequalities for vector-valued functions.

Vortex analysis of the periodic Ginzburg-Landau model

Wave equation and multiplier estimates on ax + b groups

Weakly semibounded boundary problems and sesquilinear forms

Weighted Miranda-Talenti inequality and applications to equations with discontinuous coefficients

Weighted Poincaré and Sobolev inequalites for vector fields satisfying Hörmander's condition and applications.

Well-posedness and regularity for a parabolic-hyperbolic Penrose-Fife phase field system

Well-posedness in the Gevrey classes of the Cauchy problem for a non-strictly hyperbolic equation with coefficients depending on time

Which solutions of the third problem for the Poisson equation are bounded?

Zur Abschätzung der Lösung des Dirichletschen Außenraumproblems für die Schwingungsgleichung.

Zur Regularitätstheorie der instationären Gleichungen von Navier-Stokes.

Аналитические первые интегралы нелинейных параболических уравнений и их приложения

Аналог принципа Сен-Венана для полигармонического уравнения и его приложения

Априорная оценка oeoeuoeoe выпуклых решений задачи Дирихле для уравнения Монжа-Ампера

Априорные оценки вторых производных решений нелинейных уравнений второго порядка на границе области

Currently displaying 741 – 760 of 920