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Gap between LS-category and cohomological dimension for homomorphisms of geometrically finite groups

Characterize the possible values of cat(φ) − cdp(φ) for group homomorphisms between geometrically finite groups and ascertain whether arbitrarily large gaps can occur.

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Background

The work investigates the relationship between LS-category cat(φ) and cohomological dimension cdp(φ) for group homomorphisms. Known examples show a gap of 1, but it is unclear whether larger gaps are possible, especially for geometrically finite groups.

A negative answer to the preceding inequality question (Question 6.11) would suggest constructions yielding arbitrarily large gaps between cat(φ) and cdp(φ), highlighting fundamental differences between these invariants.

References

Question 6.12. What is the gap of LS-category and cohomological dimension of group homo-

morphisms of geometrically finite groups? All known examples regarding the Question 6.12 have a gap of 1 (See [DK, DD, Gr]). Possible negative answer for Question 6.11 comes the constructing the arbitrary large gap for Question 6.12.

On the sequential topological complexity of group homomorphisms (2402.13389 - Kuanyshov, 20 Feb 2024) in Question 6.12 (Section 6), page 18