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Related papers: Automorphism groups of Moishezon threefolds

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In this short note we prove that every Jordan derivation of triangular algebras is a derivation.

Rings and Algebras · Mathematics 2007-06-14 Xuehan Cheng , Wu Jing

For a geometrically rational surface X over an arbitrary field of characteristic different from 2 and 3 that contains all roots of 1, we show that either X is birational to a product of a projective line and a conic, or the group of…

Algebraic Geometry · Mathematics 2020-08-18 Constantin Shramov , Vadim Vologodsky

We give a characterisation of quantum automorphism groups of trees. In particular, for every tree, we show how to iteratively construct its quantum automorphism group using free products and free wreath products. This can be considered a…

Quantum Algebra · Mathematics 2023-11-09 Josse van Dobben de Bruyn , Prem Nigam Kar , David E. Roberson , Simon Schmidt , Peter Zeman

We study automorphism and birational automorphism groups of varieties over fields of positive characteristic from the point of view of Jordan and $p$-Jordan property. In particular, we show that the Cremona group of rank $2$ over a field of…

Algebraic Geometry · Mathematics 2024-10-30 Yifei Chen , Constantin Shramov

Models of all the gradings on the exceptional simple Lie algebras induced by Jordan subgroups of their groups of automorphisms are provided.

Rings and Algebras · Mathematics 2008-10-16 Alberto Elduque

Let $G$ and $H$ be locally compact groups. We will show that each contractive Jordan isomorphism $\Phi\colon L^1(G)\to L^1(H)$ is either an isometric isomorphism or an isometric anti-isomorphism. We will apply this result to study isometric…

Functional Analysis · Mathematics 2024-07-02 J. Alaminos , J. Extremera , C. Godoy , A. R. Villena

We prove that for any closed smooth $4$-manifold $X$ there exists a constant $C$ with the property that each finite subgroup $G<Diff(X)$ has a subgroup $N$ which is abelian or nilpotent of class $2$, and which satisfies $[G:N]\leq C$. We…

Differential Geometry · Mathematics 2019-01-15 Ignasi Mundet i Riera , Carles Sáez-Calvo

We prove that an analogue of Jordan's theorem on finite subgroups of general linear groups holds for the groups of biregular automorphisms of elliptic ruled surfaces. This gives a positive answer to a question of Vladimir L. Popov.

Algebraic Geometry · Mathematics 2014-06-23 Yuri G. Zarhin

We call a group $G$ nilpotently Jordan of class at most $c$ $(c\in\mathbb{N})$ if there exists a constant $J\in\mathbb{Z}^+$ such that every finite subgroup $H\leqq G$ contains a nilpotent subgroup $K\leqq H$ of class at most $c$ and index…

Algebraic Geometry · Mathematics 2020-04-27 Attila Guld

In this note, we report some recent progress on the Jordan property for (birational) automorphism groups of projective varieties and compact complex varieties.

Algebraic Geometry · Mathematics 2025-08-25 Yujie Luo , Sheng Meng , De-Qi Zhang

We classify smooth Fano threefolds with infinite automorphism groups.

Algebraic Geometry · Mathematics 2021-06-11 Ivan Cheltsov , Victor Przyjalkowski , Constantin Shramov

In this article we prove that every automorphism of a universal sofic group is class preserving, i.e. preserves the conjugacy classes

Group Theory · Mathematics 2013-12-04 Liviu Paunescu

We show that if $M$ is a compact smooth manifold diffeomorphic to the total space of an orientable $S^2$ bundle over the torus $T^2$, then its diffeomorphism group does not have the Jordan property, i.e., Diff$(M)$ contains a finite…

Differential Geometry · Mathematics 2014-12-01 Balázs Csikós , László Pyber , Endre Szabó

We study automorphism groups of del Pezzo surfaces without points over a field of zero characteristic, and estimate their Jordan constants.

Algebraic Geometry · Mathematics 2025-10-06 Constantin Shramov , Anastasia Vikulova

We call a group $G$ nilpotently Jordan of class at most $c$ $(c\in\mathbb{N})$ if there exists a constant $J\in\mathbb{Z}^+$ such that every finite subgroup $H\leqq G$ contains a nilpotent subgroup $K\leqq H$ of class at most $c$ and index…

Algebraic Geometry · Mathematics 2019-12-24 Attila Guld

We study properties of continuous finite group actions on topological manifolds that hold true, for any finite group action, after possibly passing to a subgroup of index bounded above by a constant depending only on the manifold. These…

Algebraic Topology · Mathematics 2022-10-14 Ignasi Mundet i Riera

In 1869, Jordan proved that the set $\mathcal{T}$ of all finite group that can be represented as the automorphism group of a tree is containing the trivial group and it is closed under taken direct product of groups of lower order in…

Group Theory · Mathematics 2021-04-07 Somayeh Madani , Ali Reza Ashrafi

We show an analogue of Jordan's theorem for algebraic groups defined over a field $\mathbb k$ of arbitrary characteristic. As a consequence, a Jordan-type property holds for the automorphism group of any projective variety over $\mathbb k$.

Algebraic Geometry · Mathematics 2021-02-24 Fei Hu

We prove that for any closed Lorentz $4$-manifold $(M,g)$ the isometry group $Isom(M,g)$ is Jordan. Namely, there exists a constant $C$ (depending on $M$ and $g$) such that any finite subgroup $\Gamma\leq Isom(M,g)$ has an abelian subgroup…

Differential Geometry · Mathematics 2019-01-15 Ignasi Mundet i Riera

In this paper we show that any linear vector field $\mathcal{X}$ on a connected Lie group $G$ admits a Jordan decomposition and the recurrent set of the associated ow of automorphisms is given as the intersection of the fixed points of the…

Dynamical Systems · Mathematics 2020-09-11 Victor Ayala , Adriano Da Silva , Philippe Jouan