6533b85ffe1ef96bd12c1c61

RESEARCH PRODUCT

An example concerning the zero set of the Jacobian

Janne Kauhanen

subject

Discrete mathematicsPure mathematicsZero setApplied MathematicsMinor (linear algebra)Function (mathematics)Measure (mathematics)HomeomorphismDistortion (mathematics)symbols.namesakeMapping of finite distortionJacobian matrix and determinantsymbolsAlmost everywhereJacobianAnalysisMathematics

description

AbstractLet f∈W1,1(Ω,Rn) be a homeomorphism of finite distortion K. It is known that if K1/(n−1)∈L1(Ω), then the Jacobian Jf of f is positive almost everywhere in Ω. We will show that this integrability assumption on K is sharp in any Orlicz-scale: if α is increasing function (satisfying minor technical assumptions) such that limt→∞α(t)=∞, then there exists f such that K1/(n−1)/α(K)∈L1(Ω) and Jf vanishes in a set of positive measure.

https://doi.org/10.1016/j.jmaa.2005.04.060