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Bibliographic Details
Main Authors: Ebert, Johannes, Reinhold, Jens
Format: Preprint
Published: 2022
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Online Access:https://arxiv.org/abs/2203.03414
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author Ebert, Johannes
Reinhold, Jens
author_facet Ebert, Johannes
Reinhold, Jens
contents We calculate the rational cohomology of the classifying space of the diffeomorphism group of the manifolds $U_{g,1}^n:= \#^g(S^n \times S^{n+1})\setminus \mathrm{int}{D^{2n+1}}$, for large $g$ and $n$, up to approximately degree $n$. The answer is that it is a free graded commutative algebra on an appropriate set of Miller--Morita--Mumford classes. Our proof goes through the classical three-step procedure: (a) compute the cohomology of the homotopy automorphisms, (b) use surgery to compare this to block diffeomorphisms, (c) use pseudoisotopy theory and algebraic $K$-theory to get at actual diffeomorphism groups.
format Preprint
id arxiv_https___arxiv_org_abs_2203_03414
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Some rational homology computations for diffeomorphisms of odd-dimensional manifolds
Ebert, Johannes
Reinhold, Jens
Algebraic Topology
We calculate the rational cohomology of the classifying space of the diffeomorphism group of the manifolds $U_{g,1}^n:= \#^g(S^n \times S^{n+1})\setminus \mathrm{int}{D^{2n+1}}$, for large $g$ and $n$, up to approximately degree $n$. The answer is that it is a free graded commutative algebra on an appropriate set of Miller--Morita--Mumford classes. Our proof goes through the classical three-step procedure: (a) compute the cohomology of the homotopy automorphisms, (b) use surgery to compare this to block diffeomorphisms, (c) use pseudoisotopy theory and algebraic $K$-theory to get at actual diffeomorphism groups.
title Some rational homology computations for diffeomorphisms of odd-dimensional manifolds
topic Algebraic Topology
url https://arxiv.org/abs/2203.03414