TY - GEN A1 - Haller-Dintelmann, Robert A1 - Kaiser, Hans-Christoph A1 - Rehberg, Joachim T1 - Elliptic model problems including mixed boundary conditions and material heterogeneities N2 - We present model problems in three dimensions, where the operator $-\nabla \cdot \mu \nabla$ maps the Sobolev space $W^1,p_\Gamma(\Omega)$ isomorphically onto $W^-1,p_\Gamma(\Omega)$ for a $p>3$. The emphasis is here on the case where different boundary conditions meet material heterogeneities. KW - Elliptic transmission problems KW - mixed boundary problems KW - $W^1 KW - p$ regularity Y1 - 2008 UR - https://opus4.kobv.de/opus4-matheon/frontdoor/index/index/docId/463 UR - https://nbn-resolving.org/urn:nbn:de:0296-matheon-4634 ER -