activity
20112026
most citedSome finiteness results for groups of automorphisms of manifolds

18 citations · 135 across the 39 of their papers we have counts for

collaborators

49 papers

math.AT2026

Double Steinberg coinvariants for special linear groups

Tatiana Abdelnaim, David Chan, Alexander Kupers +2

For a field we study the coinvariants for the -action on the double Steinberg module and show they have a rich algebraic structure: for $n =…

math.AT2026

The Morita classes are nonzero

Alexander Kupers, Jeremy Miller, Peter Patzt

We prove that all Morita classes are nonzero using a novel description of the Hopf algebra structure on Steinberg homology. We prove anal…

math.AT2025★ 1 cited

Framed configuration spaces and exotic spheres

Manuel Krannich, Alexander Kupers, Fadi Mezher

We determine when an exotic sphere of dimension can be detected through the homotopy type of its truncated Disc-presheaf. The latter records the diagram of…

math.AT2025

Pontryagin-Weiss classes and a rational decomposition of spaces of homeomorphisms

Manuel Krannich, Alexander Kupers

We construct a rational homotopy pullback decomposition for variants of the classifying space of the group of homeomorphisms for a large class of manifolds. This has various applic…

math.AT2024

Infinity-operadic foundations for embedding calculus

Manuel Krannich, Alexander Kupers

Motivated by applications to spaces of embeddings and automorphisms of manifolds, we consider a tower of -categories of truncated right-modules over a unital -opera…

math.KT2024

Scissors automorphism groups I: Homological stability and K-theory

Alexander Kupers, Ezekiel Lemann, Cary Malkiewich +2

In any category with a reasonable notion of cover, each object has a group of scissors automorphisms. We prove that under mild conditions, the homology of this group is independent…

math.GT2024

The bounded cohomology of transformation groups of Euclidean spaces and discs

Francesco Fournier-Facio, Nicolas Monod, Sam Nariman +1

We prove that the groups of orientation-preserving homeomorphisms and diffeomorphisms of are boundedly acyclic, in all regularities. This is the first full computati…

math.GT2024

A note on homotopy and pseudoisotopy of diffeomorphisms of -manifolds

Manuel Krannich, Alexander Kupers

This note serves to record examples of diffeomorphisms of closed smooth -manifolds that are homotopic but not pseudoisotopic to the identity, and to explain why there are no…

math.GT2023

Mapping class groups of exotic tori and actions by

Mauricio Bustamante, Manuel Krannich, Alexander Kupers +1

We determine for which exotic tori of dimension the homomorphism from the group of isotopy classes of orientation-preserving diffeomorphisms of …

math.GT2023★ 1 cited

The first two k-invariants of Top/O

Alexander Kupers

We show that the first two -invariants of Top/O vanish and give some applications.

math.AT2022

Two remarks on spaces of maps between operads of little cubes

Geoffroy Horel, Manuel Krannich, Alexander Kupers

We record two facts on spaces of derived maps between the operads of little -cubes. Firstly, these mapping spaces are equivalent to the mapping spaces between the non-unit…

math.AT2022★ 4 cited

Stability of concordance embeddings

Thomas Goodwillie, Manuel Krannich, Alexander Kupers

We prove a stability theorem for spaces of smooth concordance embeddings. From it we derive various applications to spaces of concordance diffeomorphisms and homeomorphisms.

math.AT2022★ 1 cited

The Disc-structure space

Manuel Krannich, Alexander Kupers

We study the Disc-structure space of a compact smooth manifold . Informally speaking, this space measures the difference between , together with it…

math.GT2022

Mapping class groups of manifolds with boundary are of finite type

Alexander Kupers

In this note we prove that the mapping class group of a compact topological manifold with boundary is of finite type, under assumptions on its dimension and connectivity.

math.AT2021★ 10 cited

Improved homological stability for certain general linear groups

Alexander Kupers, Jeremy Miller, Peter Patzt

We prove that the general linear groups of the integers, Gaussian integers, and Eisenstein integers satisfy homological stability of slope 1 when using -coefficien…

math.AT2021

On the Torelli Lie algebra

Alexander Kupers, Oscar Randal-Williams

We prove two theorems about the Malcev Lie algebra associated to the Torelli group of a surface of genus : stably, it is Koszul and the kernel of the Johnson homomorphism consis…

math.GT2021

On Torelli groups and Dehn twists of smooth 4-manifolds

Manuel Krannich, Alexander Kupers

This note has two related but independent parts. Firstly, we prove a generalisation of a recent result of Gay on the smooth mapping class group of . Secondly, we give an alter…

math.AT2021★ 1 cited

Finiteness properties of automorphism spaces of manifolds with finite fundamental group

Mauricio Bustamante, Manuel Krannich, Alexander Kupers

Given a closed smooth manifold of even dimension with finite fundamental group, we show that the classifying space of the diffeomorphism group of …

math.AT2021★ 3 cited

Embedding calculus for surfaces

Manuel Krannich, Alexander Kupers

We prove convergence of Goodwillie-Weiss' embedding calculus for spaces of embeddings into a manifold of dimension at most two, so in particular for diffeomorphisms between surface…

math.GT2020★ 1 cited

There is no topological Fulton-MacPherson compactification

Alexander Kupers

In this note we prove that the Fulton-MacPherson compactification of configuration spaces of smooth manifolds can not be extended to topological manifolds in a natural manner, usin…

math.AT2020★ 6 cited

An -bundle over with nontrivial -genus

Manuel Krannich, Alexander Kupers, Oscar Randal-Williams

We explain the existence of a smooth -bundle over whose total space has nontrivial -genus. Combined with an argument going back to Hitchin, this answers a ques…

math.AT2020★ 1 cited

On diffeomorphisms of even-dimensional discs

Alexander Kupers, Oscar Randal-Williams

We determine for completely in degrees , far beyond the pseudoisotopy stable range. Furthermore, above th…

math.AT2020

Framings of

Alexander Kupers, Oscar Randal-Williams

We compute the set of framings of , up to homotopy and diffeomorphism relative to the boundary.

math.AT2020★ 4 cited

On the generalized Bykovskii presentation of Steinberg modules

Alexander Kupers, Jeremy Miller, Peter Patzt +1

We study presentations of the virtual dualizing modules of special linear groups of number rings, the Steinberg modules. Bykovskii gave a presentation for the Steinberg modules of…