6533b85dfe1ef96bd12bdd3f

RESEARCH PRODUCT

Mappings of finite distortion: the degree of regularity

Daniel FaracoXiao ZhongPekka Koskela

subject

Mathematics(all)Class (set theory)Pure mathematicsDegree (graph theory)Measurable functionPhysical constantGeneral MathematicsMathematical analysisDistortion (mathematics)symbols.namesakeBounded functionJacobian matrix and determinantsymbolsGravitational singularityMathematics

description

This paper investigates the self-improving integrability properties of the so-called mappings of finite distortion. Let K(x)⩾1 be a measurable function defined on a domain Ω⊂Rn,n⩾2, and such that exp(βK(x))∈Lloc1(Ω), β>0. We show that there exist two universal constants c1(n),c2(n) with the following property: Let f be a mapping in Wloc1,1(Ω,Rn) with |Df(x)|n⩽K(x)J(x,f) for a.e. x∈Ω and such that the Jacobian determinant J(x,f) is locally in L1log−c1(n)βL. Then automatically J(x,f) is locally in L1logc2(n)βL(Ω). This result constitutes the appropriate analog for the self-improving regularity of quasiregular mappings and clarifies many other interesting properties of mappings of finite distortion. Namely, we obtain novel results on the size of removable singularities for bounded mappings of finite distortion, and on the area distortion under this class of mappings.

https://doi.org/10.1016/j.aim.2003.12.009