Archivio della ricerca di Napoli "Parthenope"https://ricerca.uniparthenope.itIl sistema di repository digitale IRIS acquisisce, archivia, indicizza, conserva e rende accessibili prodotti digitali della ricerca.Sat, 07 Dec 2019 16:11:21 GMT2019-12-07T16:11:21Z10321Homeomorphisms of finite inner distortion: composition operators on Zygmund-Sobolev and Lorentz-Sobolev spaceshttp://hdl.handle.net/11367/45024Titolo: Homeomorphisms of finite inner distortion: composition operators on Zygmund-Sobolev and Lorentz-Sobolev spaces
Abstract: Letp > n-1 and α ∈ R and suppose that f: Ω →onto Ω′ is a homeomorphism in the Zygmund-Sobolev space WLp logα Lloc(Ω,Rn). Define r= p/p-n+1. Assume that u∈WLr log-α(r-1) Lloc(Ω). Then u ο f-1 ∈ BVloc(Ω′). We obtain a similar result whenever f is a homeomorphism in the Lorentz-Sobolev space WLloc p,q (Ω, Rn) with p, q > n-1 and u ∈ WLloc r,s (Ω) with r as before and s = q/q-n+1. Moreover, if we further assume that f has finite inner distortion we obtain in both cases u ο f-1 ∈ W loc 1,1 (Ω′).
Thu, 01 Jan 2015 00:00:00 GMThttp://hdl.handle.net/11367/450242015-01-01T00:00:00ZREGULARITY RESULTS FOR LOCAL MINIMIZERS OF FUNCTIONALS WITH DISCONTINUOUS COEFFICIENTShttp://hdl.handle.net/11367/59485Titolo: REGULARITY RESULTS FOR LOCAL MINIMIZERS OF FUNCTIONALS WITH DISCONTINUOUS COEFFICIENTS
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/11367/594852016-01-01T00:00:00ZExplicit Bounds and Sharp Results for the Composition Operators Preserving the Exponential Classhttp://hdl.handle.net/11367/55327Titolo: Explicit Bounds and Sharp Results for the Composition Operators Preserving the Exponential Class
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/11367/553272016-01-01T00:00:00ZBoyd Indices in Generalized Grand Lebesgue Spaces and Applicationshttp://hdl.handle.net/11367/40710Titolo: Boyd Indices in Generalized Grand Lebesgue Spaces and Applications
Thu, 01 Jan 2015 00:00:00 GMThttp://hdl.handle.net/11367/407102015-01-01T00:00:00ZBest constant and extremals for a vector Poincaré inequality with weightshttp://hdl.handle.net/11367/20259Titolo: Best constant and extremals for a vector Poincaré inequality with weights
Fri, 01 Jan 2010 00:00:00 GMThttp://hdl.handle.net/11367/202592010-01-01T00:00:00ZQuasiconformal mappings and exponentially integrable functionshttp://hdl.handle.net/11367/14722Titolo: Quasiconformal mappings and exponentially integrable functions
Abstract: We prove that a if-quasiconformal mapping f: R2 → R 2 which maps the unit disk D onto itself preserves the space EXP(D) of exponentially integrable functions over D, in the sense that u ∈ EXP(D) if and only if u o f-1 ∈ EXP(D). Moreover, if / is assumed to be conformal outside the unit disk and principal, we provide the estimate 1/1+K log K ≤ ||u o f-1||EXP(D)/||u||EXP(D)≤1+K log K for every u ε EXP(D). Similarly, we consider the distance from L∞ in EXP and we prove that if f: Ω → Ω' is a K-quasiconformal mapping and G ⊂ ⊂ Ω, then 1/K ≤ distEXP(f(G))(u o f-1, L∞(f(G)))/distEXP(f(G))(u, L∞(G)) ≤ K for every u ∈ EXP(G). We also prove that the last estimate is sharp, in the sense that there exist a quasiconformal mapping f: D → D, a domain G ⊂ ⊂ D and a function u ∈ EXP(G) such that distEXP(f(G))(u o f-1, L∞(f(G))) = K distEXP(f(G))(u, L∞(G)).
Sat, 01 Jan 2011 00:00:00 GMThttp://hdl.handle.net/11367/147222011-01-01T00:00:00ZChange of variables for $A_\infty$ weights by means of quasiconformal mappings: sharp resultshttp://hdl.handle.net/11367/28618Titolo: Change of variables for $A_\infty$ weights by means of quasiconformal mappings: sharp results
Abstract: Let f: Rn→Rn be a quasiconformal mapping whose Jacobian is denoted by Jf and let A∞ be the Muckenhoupt class of weights ω satisfying for every ball B ⊂ Rn and for some positive constant A ≥ 1 independent of B. We consider two characteristic constants ~ Ã<sub/> (ω) and G̃1 (ω) which are simultaneously finite for every ω σ A∞. We study the behaviour of the Ã∞-constant under the operator already considered by Johnson and Neugebauer [18] and establish the equivalence of the two constants G̃1(Jf ) and Ã∞(Jf-1). Our quantitative esti-mates are sharp.
Tue, 01 Jan 2013 00:00:00 GMThttp://hdl.handle.net/11367/286182013-01-01T00:00:00ZA sharp weighted Wirtinger inequality and some related functional spaceshttp://hdl.handle.net/11367/21095Titolo: A sharp weighted Wirtinger inequality and some related functional spaces
Fri, 01 Jan 2010 00:00:00 GMThttp://hdl.handle.net/11367/210952010-01-01T00:00:00ZOn the approximate
computation of singular and hypersingular integralshttp://hdl.handle.net/11367/21984Titolo: On the approximate
computation of singular and hypersingular integrals
Sat, 01 Jan 2000 00:00:00 GMThttp://hdl.handle.net/11367/219842000-01-01T00:00:00ZHigher integrability for minimizers of asymptotically convex integrals with discontinuous coefficientshttp://hdl.handle.net/11367/55848Titolo: Higher integrability for minimizers of asymptotically convex integrals with discontinuous coefficients
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/11367/558482017-01-01T00:00:00Z