Quasi-perfect scheme-maps and boundedness of the twisted inverse image functor
Abstract
For a map f: X -> Y of quasi-compact quasi-separated schemes, we discuss quasi-perfection, that is, the right adjoint f^\times of the derived functor Rf_* respects small direct sums. This is equivalent to the existence of a functorial isomorphism f^\times O_{Y} \otimes^L Lf^*(-) \to f^\times (-); to quasi-properness (preservation by Rf_* of pseudo-coherence, or just properness in the noetherian case) plus boundedness of Lf^* (finite tor-dimensionality), or of the functor f^\times; and to some other conditions. We use a globalization, previously known only for divisorial schemes, of the local definition of pseudo-coherence of complexes, as well as a refinement of the known fact that the derived category of complexes with quasi-coherent homology is generated by a single perfect complex.
Keywords
Cite
@article{arxiv.math/0611760,
title = {Quasi-perfect scheme-maps and boundedness of the twisted inverse image functor},
author = {Joseph Lipman and Amnon Neeman},
journal= {arXiv preprint arXiv:math/0611760},
year = {2011}
}
Comments
Thanks to a theorem of Bondal and van den Bergh, previously unknown to us, we can now prove our main results for quasi-compact quasi-separated (rather than just separated) schemes. To appear in Illinois J. Math. 27 pages