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Related papers: On factorization of the shift semigroup

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We give sufficient conditions on an operator space $E$ and on a semigroup of operators on a von Neumann algebra $M$ to obtain a bounded analytic or a $R$-analytic semigroup $(T_t \otimes Id_E)_{t \geq 0}$ on the vector valued noncommutative…

Operator Algebras · Mathematics 2016-02-01 Cédric Arhancet

The extension problem asks whether positive semi-definite functions on a symmetric unital subset of a discrete group can be extended to positive semi-definite functions on the whole group. It has been known at least since the work of Rudin…

Operator Algebras · Mathematics 2026-04-01 Evgenios T. A. Kakariadis , Malte Leimbach , Ivan G. Todorov , Walter D. van Suijlekom

In this paper we establish affinizations and R-matrices in the language of pro-objects, and as an application, we construct reflection functors over the localizations of quiver Hecke algebras of arbitrary finite types. This reflection…

Representation Theory · Mathematics 2025-05-02 Masaki Kashiwara , Myungho Kim , Se-jin Oh , Euiyong Park

In this paper we characterize and construct semigroups whose right regular representation is a left cancellative semigroup. These semigroups will be called left equalizer simple semigroups. For a congruence $\varrho$ on a semigroup $S$, let…

Group Theory · Mathematics 2016-05-13 Attila Nagy

To each finite-dimensional operator space $E$ is associated a commutative operator algebra $UC(E)$, so that $E$ embeds completely isometrically in $UC(E)$ and any completely contractive map from $E$ to bounded operators on Hilbert space…

Functional Analysis · Mathematics 2010-10-01 Michael T. Jury

The paper deals with the necessary and sufficient conditions for obtaining reconstruction formulae and sampling theorems for every function belonging to the principal shift invariant subspace of $L^2(\mathbb{H}^n)$, both in the time domain…

Functional Analysis · Mathematics 2019-02-06 S. Arati , R. Radha

For numerical semigroups with three generators, we study the asymptotic behavior of weighted factorization lengths, that is, linear functionals of the coefficients in the factorizations of semigroup elements. This work generalizes many…

Combinatorics · Mathematics 2021-08-16 Stephan Ramon Garcia , Christopher O'Neill , Gabe Udell

General semifinite factor representations of the diffeomorphism group of euclidean space are constructed by means of a canonical correspondence with the finite factor representations of the inductive limit unitary group. This construction…

Representation Theory · Mathematics 2007-05-23 Robert P Boyer

A unitary representation of a, possibly infinite dimensional, Lie group $G$ is called semibounded if the corresponding operators $i\dd\pi(x)$ from the derived representation are uniformly bounded from above on some non-empty open subset of…

Representation Theory · Mathematics 2012-05-24 Karl-Hermann Neeb

A suitable notion of hypercontractivity for a nonlinear semigroup $\{T_t\}$ is shown to imply Gagliardo--Nirenberg inequalities for its generator $H$, provided a subhomogeneity property holds for the energy functional $(u,Hu)$. We use this…

Functional Analysis · Mathematics 2021-06-01 Fabio Cipriani , Gabriele Grillo

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

The generalized state space $ S_{\mathcal{H}}(\mathcal{\mathcal{A}})$ of all unital completely positive (UCP) maps on a unital $C^*$-algebra $\mathcal{A}$ taking values in the algebra $\mathcal{B}(\mathcal{H})$ of all bounded operators on a…

Operator Algebras · Mathematics 2022-01-17 B. V. Rajarama Bhat , Manish Kumar

In this article, we characterize completely alternating functions on an abelian semigroup $S$ in terms of completely monotone functions on the product semigroup $S\times \mathbb Z_+$. We also discuss completely alternating sequences induced…

Functional Analysis · Mathematics 2025-09-04 Monojit Bhattacharjee , Rajkamal Nailwal

We consider symmetry operators a from the group ring C[S_N] which act on the Hilbert space H of the 1D spin-1/2 Heisenberg magnetic ring with N sites. We investigate such symmetry operators a which are self-adjoint (in a sence defined in…

Combinatorics · Mathematics 2015-05-14 Bernd Fiedler

We discuss a correlation function factorization, which relates a three-point function to the square root of three two-point functions. This factorization is known to hold for certain scaling operators at the two-dimensional percolation…

Statistical Mechanics · Physics 2015-05-13 Jacob J. H. Simmons , Peter Kleban

We prove that the negative infinitesimal generator $L$ of a semigroup of positive contractions on $L^\infty$ has a bounded $H^\infty(S_\eta^0)$-calculus on the associated Poisson semigroup-BMO space for any angle $\eta>\pi/2$, provided the…

Functional Analysis · Mathematics 2019-03-06 Tim Ferguson , Tao Mei , Brian Simanek

We consider a version of the notion of F-inverse semigroup (studied in the algebraic theory of inverse semigroups). We point out that an action of such an inverse semigroup on a locally compact space has associated a natural groupoid…

funct-an · Mathematics 2008-02-03 Alexandru Nica

This paper presents necessary and sufficient conditions for a positive bounded operator on a separable Hilbert space to be the sum of a finite or infinite collection of projections (not necessarily mutually orthogonal), with the sum…

Operator Algebras · Mathematics 2008-11-19 Victor Kaftal , Ping Wong Ng , Shuang Zhang

Let $G$ be a connected complex semisimple Lie group, $\Gamma$ be a cocompact, irreducible and torsionless lattice in $G$ and $K$ be a maximal compact subgroup of $G$. Assume $\Gamma$ acts by left multiplication and $K$ acts by right…

Complex Variables · Mathematics 2023-09-13 Pritthijit Biswas

In this paper we study the embedding problem of an operator into a strongly continuous semigroup. We obtain characterizations for some classes of operators, namely composition operators and analytic Toeplitz operators on the Hardy space…

Functional Analysis · Mathematics 2025-02-19 Isabelle Chalendar , Romain Lebreton