Per chi fosse interessato a pranzare con lo speaker, ci troviamo nell'atrio
alle 12.30
Bruno
Il Mer 19 Giu 2024, 10:39 Bruno Martelli <bruno.martelli(a)unipi.it> ha
scritto:
> Buondì,
> Con colpevole ritardo vi annuncio il seminario di geometria e topologia di
> domani.
> A presto,
> Bruno
>
> Orario: Giovedì 20 giugno, ore 14.30, aula seminari.
> Speaker: Sam Fisher (Oxford)
> Title: Maps to the circle, the integers, and L2-Betti numbers
>
> Abstract: Determining conditions implying that a manifold fibers over the
> circle is an old and interesting problem. One of the most celebrated
> results in this direction is Agol's theorem, which states that every
> hyperbolic 3-manifold has a finite cover that fibers over the circle. In
> higher dimensions, much less is known. Recently,
> Italiano--Martelli--Migliorini gave the first example of a (cusped)
> hyperbolic 5-manifold fibering over the circle, answering open questions in
> topology and geometric group theory. Hyperbolic 3-manifolds and the IMM
> example are examples of hyperbolic manifolds whose fundamental groups act
> geometrically on CAT(0) cube complexes and consequentially have RFRS
> fundamental group. In this talk, we will discuss an algebraic version of
> the fibering problem: a group algebraically fibers if it maps onto the
> integers with finitely generated kernel. In the class of RFRS groups, we
> will see that finiteness properties of the kernel are controlled by
> vanishing of L2-invariants. We will also discuss applications of these
> results to high-dimensional hyperbolic manifolds
>
