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Notes on some $$t$$-structures. (English) Zbl 1074.14018
Adolphson, Alan (ed.) et al., Geometric aspects of Dwork theory. Vol. I, II. Berlin: Walter de Gruyter (ISBN 3-11-017478-2/hbk). 711-734 (2004).
The paper under review constructs perverse sheaves in a setting which is more general than the usual. In short one replaces closed subsets by constructable subsets, or better unions of closed subsets (usually given by some condition in the codimension) by ind-constructable sets. In the new context some basic methods cease to work and the author has to deal with new technical complications. At the end he constructs theories for torsion étale sheaves of order prime to the characteristic $$p$$, of $$p$$-power, and for coherent sheaves.
For the entire collection see [Zbl 1047.14001].

##### MSC:
 14F43 Other algebro-geometric (co)homologies (e.g., intersection, equivariant, Lawson, Deligne (co)homologies) 14F30 $$p$$-adic cohomology, crystalline cohomology
##### Keywords:
perverse sheaves; constructable topology