The gluing problem does not follow from homological properties of Δ p (G)

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Abstract

Given a block b in kG where k is an algebraically closed field of characteristic p, Given a block b in kG where k is an algebraically closed field of characteristic p , there are classes α Q ∈H 2 (Aut F (Q);k × ) , constructed by Külshammer and Puig, where F is the fusion system associated to b and Q is an F -centric subgroup. The gluing problem in F has a solution if these classes are the restriction of a class α∈H 2 (F c ;k × ) . Linckelmann showed that a solution to the gluing problem gives rise to a reformulation of Alperin’s weight conjecture. He then showed that the gluing problem has a solution if for every finite group G , the equivariant Bredon cohomology group H 1 G (|Δ p (G)|;A 1 ) vanishes, where |Δ p (G)| is the simplicial complex of the non-trivial p -subgroups of G and A 1 is the coefficient functor G/H↦Hom(H,k × ) . The purpose of this note is to show that this group does not vanish if G=Σ p 2 where p≥5 .
Original languageEnglish
Pages (from-to)1–10
Number of pages10
JournalHomology, Homotopy and Applications
Volume12
Issue number1
DOIs
Publication statusPublished - 2010

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Gluing
Algebraically closed
Vanish
Subgroup
Equivariant Cohomology
Cohomology Group
Simplicial Complex
Reformulation
Functor
Fusion
Finite Group
Restriction
Coefficient
Class

Keywords

  • gluing problem

Cite this

The gluing problem does not follow from homological properties of Δ p (G). / Libman, Assaf.

In: Homology, Homotopy and Applications, Vol. 12, No. 1, 2010, p. 1–10.

Research output: Contribution to journalArticle

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