Smooth homeomorphic approximation of piecewise affine homeomorphisms

Daniel Campbell, Filip Soudský

Given any $f$ a locally finitely piecewise affine homeomorphism of $Ω\subset \rn$ onto $Δ\subset \rn$ in $W^{1,p}$, $1\le p<\infty$ and any $\epsilon >0$ we construct a smooth injective…