Deficiency, relation gap and two-dimensional groups

Let G be a finitely presented, residually finite group and let δ(G) denote the deficiency of G . Assume that every subgroup H of finite index in G satisfies δ(H)−1=|G:H|(δ(G)−1) . We conjecture that G has a two-dimensional finite classifying space K(G,1) . This conjecture is motivated by an ope...

وصف كامل

التفاصيل البيبلوغرافية
المؤلفون الرئيسيون: Kar, A, Nikolov, NV
التنسيق: Journal article
اللغة:English
منشور في: World Scientific Publishing 2023
الوصف
الملخص:Let G be a finitely presented, residually finite group and let δ(G) denote the deficiency of G . Assume that every subgroup H of finite index in G satisfies δ(H)−1=|G:H|(δ(G)−1) . We conjecture that G has a two-dimensional finite classifying space K(G,1) . This conjecture is motivated by an open question about the deficiency gradient of groups and their L2 -Betti numbers. In this note, we relate this conjecture to the relation gap problem for group presentations. We verify the pro-p version of the conjecture, as well as its higher dimensional abstract analogs.