English
Related papers

Related papers: Non-cocycle-conjugate $E_0$-semigroups on factors

200 papers

We classify all continuous tensor product systems of Hilbert spaces which are ``infinitely divisible" in the sense that they have an associated logarithmic structure. These results are applied to the theory of E_0 semigroups to deduce that…

funct-an · Mathematics 2008-02-03 William Arveson

It is well known that a nontrivial commutator in a free group is never a proper power. We prove a theorem that generalizes this fact and has several worthwhile corollaries. For example, an equation $[ x_1, y_1] \ldots [ x_k, y_k] = z^n$,…

Group Theory · Mathematics 2018-10-03 S. V. Ivanov , Anton A. Klyachko

We establish a framework for weak and strong convergence of matrix models to operator-valued semicircular systems parametrized by operator-valued covariance matrices $\eta = (\eta_{i,j})_{i,j \in I}$. Non-commutative polynomials are…

Operator Algebras · Mathematics 2025-09-30 David Jekel , Yoonkyeong Lee , Brent Nelson , Jennifer Pi

We show the existence of several new infinite families of polynomially-growing automorphisms of free groups whose mapping tori are CAT(0) free-by-cyclic groups. Such mapping tori are thick, and thus not relatively hyperbolic. These are the…

Group Theory · Mathematics 2022-09-13 Rylee Alanza Lyman

This is the second one in a series of papers classifying the factorizations of almost simple groups with nonsolvable factors. In this paper we deal with almost simple unitary groups.

Group Theory · Mathematics 2021-08-03 Cai Heng Li , Lei Wang , Binzhou Xia

We enumerate factorizations of a Coxeter element in a well generated complex reflection group into arbitrary factors, keeping track of the fixed space dimension of each factor. In the infinite families of generalized permutations, our…

Combinatorics · Mathematics 2024-02-07 Joel Brewster Lewis , Alejandro H. Morales

We construct in ZFC a countably compact group without non-trivial convergent sequences of size $2^{\mathfrak{c}}$, answering a question of Bellini, Rodrigues and Tomita. We also construct in ZFC a selectively pseudocompact group which is…

General Topology · Mathematics 2021-09-01 Artur Hideyuki Tomita , Juliane Trianon-Fraga

This paper is a continuation of the paper "Numerical Semigroups: Ap\'ery Sets and Hilbert Series". We consider the general numerical AA-semigroup, i.e., semigroups consisting of all non-negative integer linear combinations of relatively…

Commutative Algebra · Mathematics 2017-01-17 Ignacio García-Marco , Jorge L. Ramírez Alfonsín , Oystein J. Rodseth

We give a new definition of the semigroup C*-algebra of a left cancellative semigroup, which resolves problems of the construction by X. Li. Namely, the new construction is functorial, and the independence of ideals in the semigroup does…

Operator Algebras · Mathematics 2019-05-07 Marat Aukhadiev

We consider (self-adjoint) families of infinite matrices of noncommutative random variables such that the joint distribution of their entries is invariant under conjugation by a free quantum group. For the free orthogonal and…

Operator Algebras · Mathematics 2011-01-05 Stephen Curran , Roland Speicher

We describe the $C^*$-algebra of an $E$-unitary or strongly 0-$E$-unitary inverse semigroup as the partial crossed product of a commutative $C^*$-algebra by the maximal group image of the inverse semigroup. We give a similar result for the…

Operator Algebras · Mathematics 2015-12-08 David Milan , Benjamin Steinberg

This is the second in a series of papers developing a theory of total positivity for loop groups. In this paper, we study infinite products of Chevalley generators. We show that the combinatorics of infinite reduced words underlies the…

Combinatorics · Mathematics 2009-12-06 Thomas Lam , Pavlo Pylyavskyy

We give extensions of results on nonnegative matrix semigroups which deduce finiteness or boundedness of such semigroups from the corresponding local properties, e.g., from finiteness or boundedness of values of certain linear functionals…

Functional Analysis · Mathematics 2013-07-01 Roman Drnovšek , Heydar Radjavi

We study the semigroup of non-injective monoid endomorphisms of the semigroup $\boldsymbol{B}_{\omega}^{\mathscr{F}}$ with a two-elements family $\mathscr{F}$ of inductive nonempty subsets of $\omega$. We describe the structure of elements…

Group Theory · Mathematics 2024-06-24 Oleg Gutik , Inna Pozdniakova

We study almost symmetric numerical semigroups and semigroup rings. We describe a characteristic property of the minimal free resolution of the semigroup ring of an almost symmetric numerical semigroup. For almost symmetric semigroups…

Commutative Algebra · Mathematics 2018-07-03 Jürgen Herzog , Kei-ichi Watanabe

Various kinds of infinitary operations satisfying forms of associativity have been considered in the literature by various authors, including A. Tarski, C. Karp, J. H. Conway, D. Krob, N. Bedon, and C. Rispal. Applications include the…

Group Theory · Mathematics 2026-05-28 Paolo Lipparini

We construct `structure invariants' of a one-ended, finitely presented group that describe the way in which the factors of its JSJ decomposition over two-ended subgroups fit together. For groups satisfying two technical conditions, these…

Group Theory · Mathematics 2017-04-07 Christopher H. Cashen , Alexandre Martin

For an inclusion of the form $\Bbb C\subseteq M_n(\Bbb C)$, where $M_n(\Bbb C)$ is endowed with a state with diagonal weights $\lambda=(\lambda_1, ..., \lambda_n)$, we use Popa's construction, for non-tracial states, to obtain an…

Operator Algebras · Mathematics 2007-05-23 Florin G. Radulescu

Non-discrete semigroup $T_1$-topologies on the extended bicyclic semigroup $\mathscr{C}_\mathbb{Z}$ are constructed. Also, we present topological conditions, when a semigroup (shift-continuous) $T_1$-topology on $\mathscr{C}_\mathbb{Z}$ is…

Group Theory · Mathematics 2026-01-22 Oleg Gutik , Marharyta Zolotar , Oleksandra Lysetska

Nonclassical states, having no classical analogue, promise advantage in the performance in several fields of technology, such as computation, communication, sensing. This led to an escalated interest in the recent years for the generation…

Quantum Physics · Physics 2018-05-22 Kishore Thapliyal