TY  - INPR
A1  - Krupchyk, K.
A1  - Tarkhanov, Nikolai Nikolaevich
A1  - Tuomela, J.
T1  - Elliptic quasicomplexes in Boutet de Monvel algebra
N2  - We consider quasicomplexes of Boutet de Monvel operators in Sobolev spaces on a smooth compact manifold with boundary. To each quasicomplex we associate two complexes of symbols. One complex is defined on the cotangent bundle of the manifold and the other on that of the boundary. The quasicomplex is elliptic if these symbol complexes are exact away from the zero sections. We prove that elliptic quasicomplexes are Fredholm. As a consequence of this result we deduce that a compatibility complex for an overdetermined elliptic boundary problem operator is also Fredholm. Moreover, we introduce the Euler characteristic for elliptic quasicomplexes of Boutet de Monvel operators.
T3  - Preprint - (2006) 12 
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-30122
ER  - 
TY  - INPR
A1  - Krupchyk, K.
A1  - Tarkhanov, Nikolai Nikolaevich
A1  - Tuomela, J.
T1  - Generalised elliptic boundary problems
N2  - For elliptic systems of differential equations on a manifold with boundary, we prove the Fredholm property of a class of boundary problems which do not satisfy the Shapiro-Lopatinskii property. We name these boundary problems generalised elliptic, for they preserve the main properties of elliptic boundary problems. Moreover, they reduce to systems of pseudodifferential operators on the boundary which are generalised elliptic in the sense of Saks (1997).
T3  - Preprint - (2005) 23 
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-29994
ER  -