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Related papers: On certain invariants of compact quantum groups

200 papers

We propose a definition of a quantum homogeneous space of a locally compact quantum group. We show that classically it reduces to the notion of a homogeneous spaces. On the quantum level our definition goes beyond the quotient case. It…

Operator Algebras · Mathematics 2014-10-30 Pawel Kasprzak

Many invariants of finitely generated positive cancelative commutative semigroups can be studied from their Poincar\'e series. We offer and present several closed formulas for them. Moreover, those formulas have elementary proofs and are…

Commutative Algebra · Mathematics 2025-07-24 Antonio Campillo , Raquel Melgar

We give a decomposition of the equivariant Kasparov category for discrete quantum group with torsions. As an outcome, we show that the crossed product by a discrete quantum group in a certain class preserves the UCT. We then show that…

Operator Algebras · Mathematics 2021-03-22 Yuki Arano , Adam Skalski

We give examples of (i) a simple theory with a formula (with parameters) which does not fork over the empty set but has mu measure 0 for every automorphism invariant Keisler measure mu, and (ii) a definable group G in a simple theory such…

We give a dynamical characterization of categorical Morita equivalence between compact quantum groups. More precisely, by a Tannaka-Krein type duality, a unital C*-algebra endowed with commuting actions of two compact quantum groups…

Operator Algebras · Mathematics 2021-06-09 Sergey Neshveyev , Makoto Yamashita

An action of a locally compact group or quantum group on a factor is said to be strictly outer when the relative commutant of the factor in the crossed product is trivial. We show that all locally compact quantum groups can act strictly…

Operator Algebras · Mathematics 2007-05-23 Stefaan Vaes

The problem of formulating a correct notion of Laplacian on compact quantum groups (CQGs) has long been recognized as both fundamental and nontrivial. Existing constructions typically rely on selecting a specific first-order differential…

Quantum Algebra · Mathematics 2025-04-29 Heon Lee

Thoma's theorem states that a group algebra $C^*(\Gamma)$ is of type I if and only if $\Gamma$ is virtually abelian. We discuss here some similar questions for the quantum groups, our main result stating that, under suitable virtually…

Quantum Algebra · Mathematics 2018-01-04 Teodor Banica , Alexandru Chirvasitu

In this paper, we investigate structural properties of finite groups that are detected by certain group invariants arising from Dijkgraaf--Witten theory, a topological quantum field theory, in one space and one time dimension. In this…

Group Theory · Mathematics 2026-04-28 Christopher A. Schroeder , Hung P. Tong-Viet

This thesis addresses questions in representation and invariant theory of finite groups. The first concerns singularities of quotient spaces under actions of finite groups. We introduce a class of finite groups such that the quotients have…

Commutative Algebra · Mathematics 2018-03-26 Ben Blum-Smith

We define concepts of amenability and co-amenability for algebraic quantum groups in the sense of A. Van Daele. We show that co-amenability of an algebraic quantum group always implies amenability of its dual. Various necessary and/or…

Operator Algebras · Mathematics 2007-05-23 E. Bedos , G. J. Murphy , L. Tuset

We analyze bipartite matrices and linear maps between matrix algebras, which are respectively, invariant and covariant, under the diagonal unitary and orthogonal groups' actions. By presenting an expansive list of examples from the…

Quantum Physics · Physics 2021-08-11 Satvik Singh , Ion Nechita

We study quantum moment maps of $G$-invariant star products, which are a quantum analogue of the moment map for classical Hamiltonian systems. Introducing an integral representation, we show that any quantum moment map for a $G$-invariant…

Quantum Algebra · Mathematics 2007-05-23 Kentaro Hamachi

We introduce a natural generalization of the notion of strongly approximately transitive (SAT) states for actions of locally compact quantum groups. In the case of discrete quantum groups of Kac type, we show that the existence of unique…

Operator Algebras · Mathematics 2024-03-25 Mehrdad Kalantar , Fatemeh Khosravi , Mohammad S. M. Moakhar

The structure of covariant instruments is studied and a general structure theorem is derived. A detailed characterization is given to covariant instruments in the case of an irreducible representation of a locally compact group.

Mathematical Physics · Physics 2009-10-16 Claudio Carmeli , Teiko Heinosaari , Alessandro Toigo

Let X be a locally compact space with a continuous proper action of a locally compact group G. Assuming that X satisfies a certain kind of duality in equivariant bivariant Kasparov theory, we can enrich the classical construction of…

K-Theory and Homology · Mathematics 2015-10-23 Heath Emerson , Ralf Meyer

In this note we give explicit isomorphisms of 2-categories between various versions of the categorified quantum group associated to a simply-laced Kac-Moody algebra. These isomorphisms are convenient when working with the categorified…

Quantum Algebra · Mathematics 2020-12-03 Aaron D. Lauda

Twisted K-theory classes over compact Lie groups can be realized as families of Fredholm operators using the representation theory of loop groups. In this talk I want to show how to deform the Fredholm family, in the sense of quantum…

K-Theory and Homology · Mathematics 2010-08-20 Jouko Mickelsson

In this paper a sampling theory for unitary invariant subspaces associated to locally compact abelian (LCA) groups is deduced. Working in the LCA group context allows to obtain, in a unified way, sampling results valid for a wide range of…

Functional Analysis · Mathematics 2016-05-16 A. G. Garcia , M. A. Hernandez-Medina , G. Perez-Villalon

Let $G$ be a locally compact group. Consider the C$^*$-algebra $C_0(G)$ of continuous complex functions on $G$, tending to 0 at infinity. The product in $G$ gives rise to a coproduct $\Delta_G$ on the C$^*$-algebra $C_0(G)$. A locally…

Operator Algebras · Mathematics 2007-05-23 M. B. Landstad , A. Van Daele