English
Related papers

Related papers: Group actions on monoidal triangulated categories …

200 papers

Let G be an affine algebraic group and let R be an associative algebra with a rational action of G by algebra automorphisms. We study the induced G-action on the spectrum Spec R of all prime ideals of R, viewed as a topological space with…

Rings and Algebras · Mathematics 2009-03-16 Martin Lorenz

We show that for a closed embedding $\mathbb{H}\le \mathbb{G}$ of locally compact quantum groups (LCQGs) with $\mathbb{G}/\mathbb{H}$ admitting an invariant probability measure, a unitary $\mathbb{G}$-representation is type-I if its…

Operator Algebras · Mathematics 2022-03-01 Alexandru Chirvasitu

For a finite group $G$ and an arbitrary commutative ring $R$, Brou\'e has placed a Frobenius exact structure on the category of finitely generated $RG$-modules by taking the exact sequences to be those that split upon restriction to the…

Representation Theory · Mathematics 2017-06-09 Shawn Baland , Alexandru Chirvasitu , Greg Stevenson

Let $(\mathcal{A}, G, \alpha)$ be a groupoid dynamical system. We show that if $G$ is assumed to be measurewise amenable and the section algebra $A = \Gamma_0(G^{(0)}, \mathcal{A})$ is nuclear, then the associated groupoid crossed product…

Operator Algebras · Mathematics 2014-06-09 Scott M. LaLonde

After recalling basic definitions and constructions for a finite group $G$ action on a $k$-linear category we give a concise proof of the following theorem of Elagin: if $\mathcal{C} = \langle \mathcal{A}, \mathcal{B} \rangle$ is a…

Algebraic Geometry · Mathematics 2017-06-07 Evgeny Shinder

We introduce a new topological invariant of a rigidly-compactly generated tensor-triangulated category and two new notions of support. The first is based on smashing subcategories: it is unknown whether the frame of smashing subcategories…

Category Theory · Mathematics 2023-09-01 Scott Balchin , Greg Stevenson

We present some results on equivariant KK-theory in the context of tensor triangular geometry. More specifically, for G a finite group, we show that the spectrum of the tensor triangulated subcategory of KK^G generated by the tensor unit…

K-Theory and Homology · Mathematics 2011-01-13 Ivo Dell'Ambrogio

We prove the existence of various adelic-style models for rigidly small-generated tensor-triangulated categories whose Balmer spectrum is a one-dimensional Noetherian topological space. This special case of our general programme of giving…

Algebraic Topology · Mathematics 2022-03-17 Scott Balchin , J. P. C. Greenlees

It was shown by Rordam and the second named author that a countable group G admits an action on a compact space such that the crossed product is a Kirchberg algebra if, and only if, G is exact and non-amenable. This construction allows a…

Operator Algebras · Mathematics 2011-11-01 G. A. Elliott , A. Sierakowski

Consider a projective limit G of finite groups G_n. Fix a compatible family \delta^n of coactions of the G_n on a C*-algebra A. From this data we obtain a coaction \delta of G on A. We show that the coaction crossed product of A by \delta…

Operator Algebras · Mathematics 2008-05-14 David Pask , John Quigg , Aidan Sims

A central question in equivariant algebraic K-theory asks whether there exists an equivariant K-theory machine from genuine symmetric monoidal G-categories to orthogonal G-spectra that preserves equivariant algebraic structures. We answer…

Algebraic Topology · Mathematics 2024-04-04 Donald Yau

Given a Lie group $G$, a compact subgroup $K$ and a representation $\tau\in\hat K$, we assume that the algebra of $\text{End}(V_\tau)$-valued, bi-$\tau$-equivariant, integrable functions on $G$ is commutative. We present the basic facts of…

Representation Theory · Mathematics 2016-04-26 Fulvio Ricci , Amit Samanta

To any triangulated category with tensor product $(K,\otimes)$, we associate a topological space $Spc(K,\otimes)$, by means of thick subcategories of $K$, a la Hopkins-Neeman-Thomason. Moreover, to each open subset $U$ of $Spc(K,\otimes)$,…

Algebraic Geometry · Mathematics 2015-01-13 Paul Balmer

We study the derived category of pseudo-coherent complexes over a noetherian commutative ring, building on prior work by Matsui-Takahashi. Our main theorem is a computation of the Balmer spectrum of this category in the case of a discrete…

Commutative Algebra · Mathematics 2025-08-26 Beren Sanders , Yufei Zhang

We show that all amenable, minimal actions of a large class of nonamenable countable groups on compact metric spaces have dynamical comparison. This class includes all nonamenable hyperbolic groups, many HNN-extensions, nonamenable…

Operator Algebras · Mathematics 2023-03-01 Eusebio Gardella , Shirly Geffen , Julian Kranz , Petr Naryshkin

We define an action of the braid group of a simple Lie algebra on the space of imaginary roots in the corresponding quantum affine algebra. We then use this action to determine an explicit condition for a tensor product of arbitrary…

Quantum Algebra · Mathematics 2007-05-23 Vyjayanthi Chari

Given an action of a finite group on a triangulated category, we investigate under which conditions one can construct a linearised triangulated category using DG-enhancements. In particular, if the group is a finite group of automorphisms…

Algebraic Geometry · Mathematics 2015-03-16 Pawel Sosna

It was proved by Valenti and Zaicev, in 2011, that, if $G$ is an abelian group and $K$ is an algebraically closed field of characteristic zero, then any $G$-grading on the algebra of upper block triangular matrices over $K$ is isomorphic to…

Rings and Algebras · Mathematics 2019-10-22 Felipe Yukihide Yasumura

Let $G$ be a finite group acting on a small category $I$. We study functors $X \colon I \to \mathscr{C}$ equipped with families of compatible natural transformations that give a kind of generalized $G$-action on $X$. Such objects are called…

Algebraic Topology · Mathematics 2016-03-09 Emanuele Dotto , Kristian Moi

For a space X acted by a finite group $\G$, the product space $X^n$ affords a natural action of the wreath product $\Gn$. In this paper we study the K-groups $K_{\tG_n}(X^n)$ of $\Gn$-equivariant Clifford supermodules on $X^n$. We show that…

Quantum Algebra · Mathematics 2009-11-07 Weiqiang Wang