@unpublished{SavinSternin2001, author = {Savin, Anton and Sternin, Boris}, title = {Index defects in the theory of nonlocal boundary value problems and the η-invariant}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26146}, year = {2001}, abstract = {The paper deals with elliptic theory on manifolds with boundary represented as a covering space. We compute the index for a class of nonlocal boundary value problems. For a nontrivial covering, the index defect of the Atiyah-Patodi-Singer boundary value problem is computed. We obtain the Poincar{\´e} duality in the K-theory of the corresponding manifolds with singularities.}, language = {en} }