Continuity of the superposition operator on Orlicz-Sobolev spaces

Optimal Domain Spaces in Orlicz-sobolev Embeddings

We deal with Orlicz-Sobolev embeddings in open subsets of R. A necessary and sufficient condition is established for the existence of an optimal, i.e. largest possible, Orlicz-Sobolev space continuously embedded into a given Orlicz space. Moreover, the optimal Orlicz-Sobolev space is exhibited whenever it exists. Parallel questions are addressed for Orlicz-Sobolev embeddings into Orlicz spaces ...

Superposition with subunitary powers in Sobolev spaces

Let 0 < a < 1 and set Φ(t) = |t|, ∀ t ∈ R. Let 1 < p < ∞ and n ≥ 1. We prove that the superposition operator u 7→ Φ(u) maps the Sobolev space W (R) into the fractional Sobolev space W (R). We also investigate the case of more general nonlinearities. Résumé. Superposition avec des puissances sousunitaires dans les espaces de Sobolev. Pour 0 < a < 1, soit Φ(t) = |t|, ∀ t ∈ R. Soient 1 < p < ∞ et ...

Semicontinuity of Vectorial Functionals in Orlicz-sobolev Spaces

We study integral vectorial functionals F(u;) ? Z f(x; u(x); Du(x))dx where f satisses quasi-convexity assumption and its growth is controlled in term of N-functions. We obtain semicontinuity results in the weak * topology of Orlicz-Sobolev spaces.

Absolute continuity on tracks and mappings of Sobolev spaces

The present paper is concerned with the circumstances under which a function g(x,t ,...,t ) provides, via composition, a ^ 1 m mapping between Sobolev spaces. That is, we examine conditions which ensure that for every system of functions u_,...,u e W _ (Q) 1 m 1, q (where W, (Q) is the class of L functions with L summable i,q q q strong first derivatives on the domain Q, c: R )S the composite f...

Extreme Points and Rotundity of Orlicz-sobolev Spaces