Traces of BMO-Sobolev Spaces

Traces of vector-valued Sobolev Spaces

The aim of the paper is to characterize the trace space of vector-valued Sobolev spaces W p (R , E) , where E is an arbitrary Banach space. In particular, we do not assume that the underlying Banach space E has the UMD property. Vector-valued Sobolev and Besov spaces are widely used in abstract evolution equations, cf. e.g. Amann [1, 2, 4], Veraar and Weis [57] or Denk, Hieber, Prüss, Saal, and...

Traces of weighted Sobolev spaces. Old and new

We give short simple proofs of Uspenskii’s results characterizing Besov spaces as trace spaces of weighted Sobolev spaces. We generalize Uspenskii’s results and prove the optimality of these generalizations. We next show how classical results on the functional calculus in the Besov spaces can be obtained as straightforward consequences of the theory of weighted Sobolev spaces.

Traces for Fractional Sobolev Spaces with Variable Exponents

In this note we prove a trace theorem in fractional spaces with variable exponents. To be more precise, we show that if p : Ω × Ω → (1,∞) and q : ∂Ω→ (1,∞) are continuous functions such that (n− 1)p(x, x) n− sp(x, x) > q(x) in ∂Ω ∩ {x ∈ Ω: n− sp(x, x) > 0}, then the inequality ‖f‖Lq(·)(∂Ω) ≤ C { ‖f‖Lp̄(·)(Ω) + [f ]s,p(·,·) } holds. Here p̄(x) = p(x, x) and [f ]s,p(·,·) denotes the fractional semi...

Remarks on Operator Bmo Spaces

Several spaces defined according to different formulations for operator-valued functions in BMO are defined and studied.

Sobolev Spaces