Displaying 301 – 320 of 4028

Showing per page

An elementary proof of Marcellini Sbordone semicontinuity theorem

Tomáš G. Roskovec, Filip Soudský (2023)

Kybernetika

The weak lower semicontinuity of the functional F ( u ) = Ω f ( x , u , u ) d x is a classical topic that was studied thoroughly. It was shown that if the function f is continuous and convex in the last variable, the functional is sequentially weakly lower semicontinuous on W 1 , p ( Ω ) . However, the known proofs use advanced instruments of real and functional analysis. Our aim here is to present a proof understandable even for students familiar only with the elementary measure theory.

An elliptic semilinear equation with source term involving boundary measures: the subcritical case.

Marie Françoise Bidaut-Véron, Laurent Vivier (2000)

Revista Matemática Iberoamericana

We study the boundary behaviour of the nonnegative solutions of the semilinear elliptic equation in a bounded regular domain Ω of RN (N ≥ 2),⎧   Δu + uq = 0,   in Ω⎨⎩   u = μ,      on ∂Ωwhere 1 < q < (N + 1)/(N - 1) and μ is a Radon measure on ∂Ω. We give a priori estimates and existence results. The lie on the study of superharmonic functions in some weighted Marcinkiewicz spaces.

An example of a reflexive Lorentz Gamma space with trivial Boyd and Zippin indices

Alexei Karlovich, Eugene Shargorodsky (2021)

Czechoslovak Mathematical Journal

We show that for every p ( 1 , ) there exists a weight w such that the Lorentz Gamma space Γ p , w is reflexive, its lower Boyd and Zippin indices are equal to zero and its upper Boyd and Zippin indices are equal to one. As a consequence, the Hardy-Littlewood maximal operator is unbounded on the constructed reflexive space Γ p , w and on its associate space Γ p , w ' .

Currently displaying 301 – 320 of 4028