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Related papers: Equivariant K-stability under finite group action

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We show that for a K-unstable Fano variety, any divisorial valuation computing its stability threshold induces a non-trivial special test configuration preserving the stability threshold. When such a divisorial valuation exists, we show…

Algebraic Geometry · Mathematics 2022-12-21 Harold Blum , Yuchen Liu , Chuyu Zhou

We consider the semi-direct products $G=\mathbb Z^2\rtimes GL_2(\mathbb Z), \mathbb Z^2\rtimes SL_2(\mathbb Z)$ and $\mathbb Z^2\rtimes\Gamma(2)$ (where $\Gamma(2)$ is the congruence subgroup of level 2). For each of them, we compute both…

Operator Algebras · Mathematics 2023-11-28 Ramon Flores , Sanaz Pooya , Alain Valette

We prove various results involving arcs - which generalise test configurations - within the theory of K-stability. Our main result characterises coercivity of the Mabuchi functional on spaces of Fubini-Study metrics in terms of uniform…

Algebraic Geometry · Mathematics 2024-09-23 Ruadhaí Dervan , Rémi Reboulet

We prove that for a finitely generated linear group G over a field of positive characteristic the family of quotients by finite subgroups has finite asymptotic dimension. We use this to show that the K-theoretic assembly map for the family…

Algebraic Topology · Mathematics 2021-05-28 Daniel Kasprowski

A. Vistoli proved a decomposition theorem for the rational equivariant algebraic K-theory of a variety under the action of a finite group $G$. We generalize his result to more general algebraic (co)homology theories having the Mackey…

Algebraic Geometry · Mathematics 2025-05-21 Francesco Sala

We establish an algebraic approach to prove the properness of moduli spaces of K-polystable Fano varieties and reduce the problem to a conjecture on destabilizations of K-unstable Fano varieties. Specifically, we prove that if the stability…

Algebraic Geometry · Mathematics 2021-07-20 Harold Blum , Daniel Halpern-Leistner , Yuchen Liu , Chenyang Xu

For a connected simply connected semisimple algebraic group $G$ we prove existence of invariant tensors in tensor powers of rational $G$-modules and establish relations between existence of such invariant tensors and stability of diagonal…

Representation Theory · Mathematics 2011-01-10 Artem Anisimov

Assume that a projective variety together with a polarization is uniformly K-stable. If the polarization is canonical or anti-canonical, then the projective variety is uniformly K-stable with respects to any polarization sufficiently close…

Algebraic Geometry · Mathematics 2017-09-26 Kento Fujita

The 'degree of k-step nilpotence' of a finite group G is the proportion of the tuples (x_1,...,x_{k+1}) in G^{k+1} for which the simple commutator [x_1,...,x_{k+1}] is equal to the identity. In this paper we study versions of this for an…

Group Theory · Mathematics 2025-12-04 Armando Martino , Matthew Tointon , Motiejus Valiunas , Enric Ventura

The goal of this paper is to prove the Riemann-Roch isomorphism for the higher equivariant K-theory of varieties with action of a linear algebraic group.

Algebraic Geometry · Mathematics 2009-06-10 Amalendu Krishna

We study the classification of group actions on C*-algebras up to equivariant KK-equivalence. We show that any group action is equivariantly KK-equivalent to an action on a simple, purely infinite C*-algebra. We show that a conjecture of…

K-Theory and Homology · Mathematics 2021-08-25 Ralf Meyer

In this article, we introduce the notion of mutation semigroup algebras. This concept simultaneously generalizes cluster algebras and semigroup algebras. We show that, under some mild conditions on the singularities, the spectrum $U={\rm…

Algebraic Geometry · Mathematics 2025-12-29 Joshua Enwright , Luca Francone , Joaquín Moraga , Hunter Spink

We state the generating hypothesis in the homotopy category of G-spectra for a compact Lie group G, and prove that if G is finite, then the generating hypothesis implies the strong generating hypothesis, just as in the non-equivariant case.…

Algebraic Topology · Mathematics 2014-10-01 Anna Marie Bohmann

Generalizing a construction of Wolfgang L\"uck and Bob Oliver, we define a good equivariant cohomology theory on the category of proper G-CW complexes when G is an arbitrary Lie group (possibly non-compact). This is done by constructing an…

Algebraic Topology · Mathematics 2010-11-02 Clément de Seguins Pazzis

Let $G$ be a real semisimple Lie group with finite centre and without compact factors, $Q<G$ a parabolic subgroup and $X$ a homogeneous space of $G$ admitting an equivariant projection on the flag variety $G/Q$ with fibres given by copies…

Dynamical Systems · Mathematics 2022-11-15 Alexander Gorodnik , Jialun Li , Cagri Sert

For any finite group G, we show that the 2-local G-equivariant stable homotopy category, indexed on a complete G-universe, has a unique equivariant model in the sense of Quillen model categories. This means that the suspension functor,…

Algebraic Topology · Mathematics 2016-09-21 Irakli Patchkoria

We prove that all general smooth Fano threefolds of Picard rank $3$ and degree $14$ are K-stable, where the generality condition is stated explicitly.

Algebraic Geometry · Mathematics 2024-05-22 Grigory Belousov , Konstantin Loginov

We show that the finiteness of the fundamental groups of the smooth locus of lower dimensional log Fano pairs would imply the finiteness of the local fundamental group of klt singularities. As an application, we verify that the local…

Algebraic Geometry · Mathematics 2019-02-20 Zhiyu Tian , Chenyang Xu

In this paper, we compute Tian's $\alpha_{m,k}^{K\times K}$-invariant on a polarized $G$-group compactification, where $K$ denotes a maximal compact subgroup of a connected complex reductive group $G$. We prove that Tian's conjecture (see…

Differential Geometry · Mathematics 2020-06-08 Yan Li , Xiaohua Zhu

Fix K a p-adic field and denote by G_K its absolute Galois group. Let K_infty be the extension of K obtained by adding (p^n)-th roots of a fixed uniformizer, and G_\infty its absolute Galois group. In this article, we define a class of…

Number Theory · Mathematics 2007-09-14 Xavier Caruso , Tong Liu