2024/04/24 by Katada, Mai
#20F28 #20J06 #Algebraic Topology (math.AT) #FOS: Mathematics #Group Theory (math.GR)
paper · doi:10.48550/arxiv.2404.15901
The IA-automorphism group IAn of the free group Fn of rank n is a normal subgroup of the automorphism group Aut(Fn) of Fn. We study the Albanese homology of IAn, which is the quotient of the rational homology of IAn defined as the image of the map induced by the abelianization map of IAn on homology. The Albanese homology of IAn is an algebraic GL(n,ℚ)-representation. We determine the representation structure of the Albanese homology of IAn for n greater than or equal to three times the homological degree. We also determine the structure of the stable Albanese homology of the analogue of IAn to the outer automorphism group of Fn. Moreover, we identify the relation between the stable Albanese (co)homology of IAn and the stable cohomology of Aut(Fn) with certain twisted coefficients.