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Related papers: Homological stability fails for the Cremona groups

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For each d we construct CAT(0) cube complexes on which Cremona groups rank d act by isometries. From these actions we deduce new and old group theoretical and dynamical results about Cremona groups. In particular, we study the dynamical…

Algebraic Geometry · Mathematics 2021-06-21 Anne Lonjou , Christian Urech

We give a sharp bound for orders of elementary abelian 2-groups of birational automorphisms of rationally connected threefolds.

Algebraic Geometry · Mathematics 2016-01-29 Yuri Prokhorov

In this paper we study homological stability for spaces ${\rm Hom}(\mathbb{Z}^n,G)$ of pairwise commuting $n$-tuples in a Lie group $G$. We prove that for each $n\geqslant 1$, these spaces satisfy rational homological stability as $G$…

Algebraic Topology · Mathematics 2021-03-16 Daniel A. Ramras , Mentor Stafa

We improve homological stability ranges for the orthogonal group, special orthogonal group, elementary orthogonal group and the spin group over a commutative local ring $R$ with infinite residue field such that $2 \in R^{*}$.

K-Theory and Homology · Mathematics 2025-12-08 Marco Schlichting , Sunny Sood

We prove a general homological stability theorem for certain families of groups equipped with product maps, followed by two theorems of a new kind that give information about the last two homology groups outside the stable range. (These…

Algebraic Topology · Mathematics 2020-07-13 Richard Hepworth

We compute the rational stable homology of the automorphism groups of free nilpotent groups. These groups interpolate between the general linear groups over the ring of integers and the automorphism groups of free groups, and we employ…

K-Theory and Homology · Mathematics 2019-08-02 Markus Szymik

Consider a Cremona group endowed with the Euclidean topology introduced by Blanc and Furter. It makes it a Hausdorff topological group that is not locally compact nor metrisable. We show that any sequence of elements of the Cremona group of…

Algebraic Geometry · Mathematics 2023-02-08 Hannah Bergner , Susanna Zimmermann

The homology groups of the automorphism group of a free group are known to stabilize as the number of generators of the free group goes to infinity, and this paper relativizes this result to a family of groups that can be defined in terms…

Geometric Topology · Mathematics 2014-11-11 Allen Hatcher , Nathalie Wahl

The problem of homological stability helps us to catch the structure of group homology. We calculate homological stability of special orthogonal groups, and we also calculate the stability of orthogonal groups with determinant-twisted…

K-Theory and Homology · Mathematics 2015-11-04 Masayuki Nakada

We show that the homology of strata of abelian differentials stabilizes in a range where the number of simple zeros is large relative to the homological degree. In this range, we show that the rational cohomology agrees with the restriction…

Algebraic Geometry · Mathematics 2026-03-26 Philip Tosteson

We classify all finite subgroups of the plane Cremona group which have a fixed point. In other words, we determine all rational surfaces X with an action of a finite group G such that X is equivariantly birational to a surface which has a…

Algebraic Geometry · Mathematics 2016-01-05 Igor Dolgachev , Alexander Duncan

We prove a stability theorem for families of holomorphically-parallelizable manifolds in the category of Hermitian manifolds.

Complex Variables · Mathematics 2015-07-13 Daniele Angella , Adriano Tomassini

We prove a slope 1 stability range for the homology of the symplectic, orthogonal and unitary groups with respect to the hyperbolic form, over any fields other than $F_2$, improving the known range by a factor 2 in the case of finite…

Algebraic Topology · Mathematics 2020-05-06 David Sprehn , Nathalie Wahl

A pair of graphs $(\Gamma,\Sigma)$ is said to be stable if the full automorphism group of $\Gamma\times\Sigma$ is isomorphic to the product of the full automorphism groups of $\Gamma$ and $\Sigma$ and unstable otherwise, where…

Combinatorics · Mathematics 2022-10-14 Yan-Li Qin , Binzhou Xia , Sanming Zhou

In this paper we prove homological stability for certain subgroups of surface braid groups. Alternatively, this is equivalent to proving homological stability for configurations of subsets of exactly $\xi$ points in a surface as we increase…

Algebraic Topology · Mathematics 2014-10-06 TriThang Tran

We present some (unfortunately not all) known properties on the Cremona group; when it's possible we mentioned links with the most known group of polynomial automorphisms of the affine plane. The mentioned properties are essentially…

Algebraic Geometry · Mathematics 2009-09-22 Julie Déserti

Exploring Bass' Triangulability Problem on unipotent algebraic subgroups of the affine Cremona groups, we prove a triangulability criterion, the existence of nontriangulable connected solvable affine algebraic subgroups of the Cremona…

Algebraic Geometry · Mathematics 2015-10-16 Vladimir L. Popov

Associated to every group with a weak spherical Tits system of rank n+1 with an appropriate rank n subgroup, we construct a relative spectral sequence involving group homology of Levi subgroups of both groups. Using the fact that such Levi…

K-Theory and Homology · Mathematics 2012-09-05 Jan Essert

We explicitly study the extremal stability of configuration spaces of complex projective spaces of any dimension, and show that the homology groups are vanish in extremal stable range. As a consequence, we give an affirmative answer of the…

Algebraic Topology · Mathematics 2022-06-24 Muhammad Yameen

We study the algebraic structure of the $n$-dimensional Cremona group and show that it is not an algebraic group of infinite dimension (ind-group) if $n\ge 2$. We describe the obstruction to this, which is of a topological nature. By…

Algebraic Geometry · Mathematics 2013-08-26 Jérémy Blanc , Jean-Philippe Furter