6533b85dfe1ef96bd12bdccd

RESEARCH PRODUCT

L 2-topological invariants of 3-manifolds

John LottWolfgang Lück

subject

Discrete mathematicsExact sequenceMathematics::Operator AlgebrasBetti numberGeneral MathematicsMathematics::Spectral TheoryMathematics::Algebraic TopologyManifoldsymbols.namesakeChain (algebraic topology)Von Neumann algebraGromov–Witten invariantsymbolsAlgebraic numberGeometrization conjectureMathematics

description

We give results on theL2-Betti numbers and Novikov-Shubin invariants of compact manifolds, especially 3-manifolds. We first study the Betti numbers and Novikov-Shubin invariants of a chain complex of Hilbert modules over a finite von Neumann algebra. We establish inequalities among the Novikov-Shubin invariants of the terms in a short exact sequence of chain complexes. Our algebraic results, along with some analytic results on geometric 3-manifolds, are used to compute theL2-Betti numbers of compact 3-manifolds which satisfy a weak form of the geometrization conjecture, and to compute or estimate their Novikov-Shubin invariants.

https://doi.org/10.1007/bf01241121