Coherence from vanishing second L2-Betti number

Let XX be an aspherical two-complex and let G=π1(X)G=\pi_1(X) be its fundamental group. Say that GG has trivial second L2L^2-Betti number when b2(2)(G)=0b_2^{(2)}(G)=0. Betti coherence conjecture. If GG has trivial second L2L^2-Betti number, then GG is coherent. The paper notes that a homological version follows when GG satisfies the strong Atiyah conjecture, but leaves the coherence conjecture open in general.

Sources & referencesView supporting material

Primary source

Andrei Jaikin-Zapirain and Marco Linton, “On the coherence of one-relator groups and their group algebras”, arXiv:2303.05976 (2025).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.