The topology of definable sets in an o-minimal expansion of a group is not fully understood due to the lack of a triangulation theorem. Despite the general validity of the cell decomposition theorem, we do not know whether any definably compact set is a definable CW-complex. Moreover the closure of an o-minimal cell can have arbitrarily high Betti numbers. Nevertheless we prove that the cohomology groups of a definably compact set over an o-minimal expansion of a group are finitely generated and invariant under elementary extensions and expansions of the language.
O-Minimal cohomology: Finiteness and invariance results / Berarducci, Alessandro; Fornasiero, Antongiulio. - In: JOURNAL OF MATHEMATICAL LOGIC. - ISSN 0219-0613. - STAMPA. - 9:(2009), pp. 167-182. [10.1142/S0219061309000859]
O-Minimal cohomology: Finiteness and invariance results
Fornasiero, Antongiulio
2009
Abstract
The topology of definable sets in an o-minimal expansion of a group is not fully understood due to the lack of a triangulation theorem. Despite the general validity of the cell decomposition theorem, we do not know whether any definably compact set is a definable CW-complex. Moreover the closure of an o-minimal cell can have arbitrarily high Betti numbers. Nevertheless we prove that the cohomology groups of a definably compact set over an o-minimal expansion of a group are finitely generated and invariant under elementary extensions and expansions of the language.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.