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Related papers: Projectivity of modules over Segal algebras

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We study various operator homological properties of the Fourier algebra $A(G)$ of a locally compact group $G$. Establishing the converse of two results of Ruan and Xu, we show that $A(G)$ is relatively operator 1-projective if and only if…

Operator Algebras · Mathematics 2018-05-24 Jason Crann , Zsolt Tanko

We perform a general study of the structure of locally compact modules over compactly generated abelian groups. We obtain a devissage result for such modules of the form "compact-by-sheer-by-discrete", and then study more specifically the…

Group Theory · Mathematics 2025-08-28 Yves Cornulier

We discover a class of projective self-dual algebraic varieties. Namely, we consider actions of isotropy groups of complex symmetric spaces on the projectivized nilpotent varieties of isotropy modules. For them, we classify all orbit…

Analysis of PDEs · Mathematics 2007-05-23 Vladimir L. Popov , Evgueni A. Tevelev

In this paper we apply a recently proposed algebraic theory of integration to projective group algebras. These structures have received some attention in connection with the compactification of the $M$ theory on noncommutative tori. This…

Mathematical Physics · Physics 2009-10-31 R. Casalbuoni

Algebras defined over fields of characteristic zero and positive characteristic usually do not behave the same way. However, for certain algebras, for example the group algebras, they behave the same way as the characteristic zero case at…

Representation Theory · Mathematics 2025-02-28 David J. Benson , Kay Jin Lim

Let $V$ be a vertex operator algebra and $g$ an automorphism of finite order. We construct an associative algebra $A_g(V)$ and a pair of functors between the category of $A_g(V)$-modules and a certain category of admissible $g$-twisted…

q-alg · Mathematics 2008-02-03 Chongying Dong , Haisheng Li , Geoffrey Mason

We study the algebra $\mathfrak{M}^{\infty,\mathrm{dec}}(G)$ of decomposable Fourier multipliers on the group von Neumann algebra $\mathrm{VN}(G)$ of a locally compact group $G$, and its relation to the Fourier-Stieltjes algebra…

Functional Analysis · Mathematics 2025-04-01 Cédric Arhancet , Christoph Kriegler

We show that the biflatness - in the sense of A. Ya. Helemskii - of the Fourier algebra $A(G)$ of a locally compact group $G$ forces $G$ to either have an abelian subgroup of finite index or to be non-amenable without containing $F_2$, the…

Functional Analysis · Mathematics 2009-06-01 Volker Runde

We discuss convergence in the Fourier algebra A(G) of a locally compact group G and provide a new characterisation of the local spectral sets of G.

Functional Analysis · Mathematics 2024-12-10 Jean Ludwig , Lyudmila Turowska

Let $G$ be a compact connected Lie group. The question of when a weighted Fourier algebra on $G$ is completely isomorphic to an operator algebra will be investigated in this paper. We will demonstrate that the dimension of the group plays…

Functional Analysis · Mathematics 2014-01-31 Mahya Ghandehari , Hun Hee Lee , Ebrahim Samei , Nico Spronk

We consider projectivity and injectivity of Hilbert C*-modules in the categories of Hilbert C*-(bi-)modules over a fixed C*-algebra of coefficients (and another fixed C*-algebra represented as bounded module operators) and bounded…

Operator Algebras · Mathematics 2008-02-18 Michael Frank , Vern I. Paulsen

We consider the issue of describing all self-adjoint idempotents (projections) in $L^1(G)$ when $G$ is a unimodular locally compact group. The approach is to take advantage of known facts concerning subspaces of the Fourier-Stieltjes and…

Representation Theory · Mathematics 2015-11-02 Mahmood Alaghmandan , Mahya Ghandehari , Nico Spronk , Keith F. Taylor

Fix a manifold M, and let V be an infinite dimensional Lie algebra of vector fields on M. Assume that V contains a finite dimensional semisimple maximal subalgebra A, the projective or conformal subalgebra. A projective or conformal…

Representation Theory · Mathematics 2015-12-17 Charles H. Conley

In this paper, we first show that for an acyclic gentle algebra A, the irreducible components of any moduli space of A-modules are products of projective spaces. Next, we show that the nice geometry of the moduli spaces of modules of an…

Representation Theory · Mathematics 2014-07-30 Andrew T. Carroll , Calin Chindris

The aim of this paper is to introduce and study a large class of $\mathfrak{g}$-module algebras which we call factorizable by generalizing the Gauss factorization of (square or rectangular) matrices. This class includes coordinate algebras…

Representation Theory · Mathematics 2018-01-31 Arkady Berenstein , Karl Schmidt

An $L^2$ Fourier restriction argument of Bak and Seeger is abstracted to the setting of locally compact abelian groups. This is used to prove new restriction estimates for varieties lying in modules over local fields or rings of integers…

Classical Analysis and ODEs · Mathematics 2018-01-11 Jonathan Hickman , James Wright

For a connected Lie group G it was shown by Lee, Ludwig, Samei and Spronk that its Fourier algebra A(G) is weakly amenable only if G is abelian. We extend this result to general connected locally compact groups, extending an approach…

Functional Analysis · Mathematics 2023-05-24 Viktor Losert

We give sufficient conditions for the affinity of Etingof's sheaves of Cherednik algebras on projective space. To do this we introduce the notion of pull-back of modules under certain flat morphisms.

Representation Theory · Mathematics 2016-01-20 Gwyn Bellamy , Maurizio Martino

In this paper, we introduce a homological notion of left $\phi$-biprojectivity for Banach algebras, where $\phi$ is a non-zero multiplicative linear functional. We show that for a locally compact group $G$, the Segal algebra $S(G)$ is left…

Functional Analysis · Mathematics 2021-10-28 Amir Sahami

We develop a suitable version of the stable module category of a finite group G over an arbitrary commutative ring k. The purpose of the construction is to produce a compactly generated triangulated category whose compact objects are the…

Representation Theory · Mathematics 2012-08-08 Dave Benson , Srikanth B. Iyengar , Henning Krause , Greg Stevenson