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There has been proposed a new method of the constructing of the basic functions for spaces of tensor representations of the Lie groups with the help of the generalized Casimir operator. In the definition of the operator there were used the…

Mathematical Physics · Physics 2015-06-26 V. D. Gladush , R. A. Konoplya

We present a generalization of Krein-\v{S}mul'jan theorem which involves several operators. Given bounded selfadjoint operators $A,B_1,\ldots,B_m$ acting on a Hilbert space $\mathcal{H}$, we provide sufficient conditions to determine…

Functional Analysis · Mathematics 2025-07-24 Santiago gonzalez Zerbo , Alejandra Maestripieri , Francisco Martínez Pería

In the dimer model, a configuration consists of a perfect matching of a fixed graph. If the underlying graph is planar and bipartite, such a configuration is associated to a height function. For appropriate "critical" (weighted) graphs,…

Probability · Mathematics 2014-07-24 Julien Dubédat

We consider divergence-form parabolic equation with measurable uniformly elliptic matrix and the vector field in a large class containing, in particular, the vector fields in $L^p$, $p>d$, as well as some vector fields that are not even in…

Analysis of PDEs · Mathematics 2021-04-06 D. Kinzebulatov , Yu. A. Semenov

We develop a systematic theory of eventually positive semigroups of linear operators mainly on spaces of continuous functions. By eventually positive we mean that for every positive initial condition the solution to the corresponding Cauchy…

Functional Analysis · Mathematics 2015-12-01 Daniel Daners , Jochen Glück , James B. Kennedy

This is first of series papers on new two-side Gaussian bounds for the heat kernel $H(x,y,t)$ on a complete manifold $(M,g)$. In this paper, on a complete manifold $M$ with $Ric(M)\geq 0$, we obtain new two-side Gaussian bounds for the heat…

Differential Geometry · Mathematics 2020-01-01 Xiangjin Xu

The Wigner-Eckart theorem is a well known result for tensor operators of SU(2) and, more generally, any compact Lie group. This paper generalises it to arbitrary Lie groups, possibly non-compact. The result relies on knowledge of recoupling…

Mathematical Physics · Physics 2015-09-21 Giuseppe Sellaroli

Let G be a locally compact group, let X be a universal proper G-space, and let Z be a G-equivariant compactification of X that is H-equivariantly contractible for each compact subgroup H of G. Let W be the resulting boundary. Assuming the…

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

Let $G$ denote an infinite-dimensional Heisenberg-like group, which is a class of infinite-dimensional step 2 stratified Lie groups. We consider holomorphic functions on $G$ that are square integrable with respect to a heat kernel measure…

Probability · Mathematics 2011-11-16 Maria Gordina , Tai Melcher

In this paper, we revisit the Riemann--Liouville analytic semigroup. In particular, we completely characterize the membership to the Schatten class $S^r$ on $L^2(0,1)$, as well as the membership to the class of nuclear operators on…

Functional Analysis · Mathematics 2026-02-03 Ihab Alam , Isabelle Chalendar , Fida El Chami , Emmanuel Fricain , Pascal Lefèvre

This paper discusses the existence of gradient estimates for second order hypoelliptic heat kernels on manifolds. It is now standard that such inequalities, in the elliptic case, are equivalent to a lower bound on the Ricci tensor of the…

Analysis of PDEs · Mathematics 2009-02-06 Tai Melcher

We give a uniform interpretation of the classical continuous Chebyshev's and Hahn's orthogonal polynomials of discrete variable in terms of Feigin's Lie algebra gl(N), where N is any complex number. One can similarly interpret Chebyshev's…

Representation Theory · Mathematics 2015-06-26 Dimitry Leites , Alexander Sergeev

In view of controlling finite dimensional open quantum systems, we provide a unified Lie-semigroup framework describing the structure of completely positive trace-preserving maps. It allows (i) to identify the Kossakowski-Lindblad…

Quantum Physics · Physics 2010-12-07 G. Dirr , U. Helmke , I. Kurniawan , T. Schulte-Herbrueggen

In this article we consider means of positive operators on a Hilbert space. We extend the theory of matrix power means to arbitrary operator means in the sense of Kubo-Ando. The basis of the extension is relying on ideas coming from…

Functional Analysis · Mathematics 2013-03-22 Miklós Pálfia

We prove a subelliptic estimate for systems of complex vector fields under some assumptions that generalize the essential pseudoconcavity for $CR$ manifolds and H\"ormander's bracket condition for real vector fields. Applications are given…

Analysis of PDEs · Mathematics 2010-12-20 Andrea Altomani , C. Denson Hill , Mauro Nacinovich , Egmont Porten

The tensor and exterior squares of a completely continuous non-negative linear operator $A$ acting in the ideal space $X(\Omega)$ are studied. The theorem representing the point spectrum (except, probably, zero) of the tensor square $A…

Spectral Theory · Mathematics 2008-12-05 Olga Y. Kushel , Petr P. Zabreiko

The Cohn-Umans (FOCS '03) group-theoretic framework for matrix multiplication produces fast matrix multiplication algorithms from three subsets of a finite group $G$ satisfying a simple combinatorial condition (the Triple Product Property).…

Group Theory · Mathematics 2025-08-20 Jonah Blasiak , Henry Cohn , Joshua A. Grochow , Kevin Pratt , Chris Umans

We investigate the two-dimensional lattice U(1) gauge-Higgs model with a topological term, employing L\"uscher's admissibility condition. The standard Monte Carlo simulation for this model is hindered not only by the complex action problem…

High Energy Physics - Lattice · Physics 2025-01-28 Shinichiro Akiyama , Yoshinobu Kuramashi

Let a family of gradient Gaussian vector fields on $ \mathbb{Z}^d $ be given. We show the existence of a uniform finite range decomposition of the corresponding covariance operators, that is, the covariance operator can be written as a sum…

Mathematical Physics · Physics 2012-02-07 Stefan Adams , Roman Kotecký , Stefan Müller

We study integral kernels of strongly continuous semigroups on Lebesgue spaces over metric measure spaces. Based on semigroup smoothing properties and abstract Morrey-type inequalities, we give sufficient conditions for H\"older or…

Functional Analysis · Mathematics 2024-01-18 Patrizio Bifulco , Delio Mugnolo