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Related papers: Algebraic representations of von Neumann algebras

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A real Lie algebra with a compatible Hilbert space structure (in the sense that the scalar product is invariant) is called a Hilbert-Lie algebra. Such Lie algebras are natural infinite-dimensional analogues of the compact Lie algebras; in…

Representation Theory · Mathematics 2017-11-02 Timothée Marquis , Karl-Hermann Neeb

Leibniz algebras are certain generalization of Lie algebras. In this paper we give the classification of four dimensional non-Lie nilpotent Leibniz algebras. We use the canonical forms for the congruence classes of matrices of bilinear…

Rings and Algebras · Mathematics 2015-11-24 Ismail Demir , Kailash C. Misra , Ernie Stitzinger

In this paper, we are interested in the construction of a bilinear pseudodifferential calculus. We define some symbolic classes which contains those of Coifman-Meyer. These new classes allow us to consider operators closely related to the…

Classical Analysis and ODEs · Mathematics 2008-02-21 Frederic Bernicot

Let k be a field of characteristic zero. We consider graded subalgebras A of k[x_1,...,x_m]/(x_1^2,...,x_m^2) generated by d linearly independant linear forms. Representations of matroids over k provide a natural description of the…

Combinatorics · Mathematics 2007-05-23 David G. Wagner

The algebra of functions on kappa-Minkowski noncommutative spacetime is studied as algebra of operators on Hilbert spaces. The representations of this algebra are constructed and classified. This new approach leads to a natural construction…

High Energy Physics - Theory · Physics 2008-11-26 Alessandra Agostini

In this paper we introduce a new algebraic device, which enables us to treat the quaternions as though they were a commutative field. This is of interest both for its own sake, and because it can be applied to develop an "algebraic…

Differential Geometry · Mathematics 2007-05-23 Dominic Joyce

We characterize injectivity of von Neumann algebras in terms of factoring bilinear maps as products of linear maps.

Operator Algebras · Mathematics 2007-05-23 Allan M. Sinclair , Roger R. Smith

We study maximal subalgebras of an arbitrary finite dimensional algebra over a field, and obtain full classification/description results of such algebras. This is done by first obtaining a complete classification in the semisimple case, and…

Rings and Algebras · Mathematics 2017-08-31 Miodrag Iovanov , Alexander Sistko

This is an expository book on unitary representations of topological groups, and of several dual spaces, which are spaces of such representations up to some equivalence. The most important notions are defined for topological groups, but a…

Group Theory · Mathematics 2019-12-17 Bachir Bekka , Pierre de la Harpe

The Langlands functoriality conjecture envisaged in the bisemialgebra framework is proved to correspond to the nonorthogonal completely reducible cuspidal representations of the bilinear algebraic semigroups.

Representation Theory · Mathematics 2007-05-23 Christian Pierre

In this paper we suggest an approach for constructing an L1-type space for a positive selfadjoint operator affiliated with von Neumann algebra. For such operator we intro- duce a seminorm, and prove that it is a norm if and only if the…

Operator Algebras · Mathematics 2020-10-21 Andrej Novikov

A variant of the Archimedean Positivstellensatz is proved which is based on Archimedean semirings or quadratic modules of generating subalgebras. It allows one to obtain representations of strictly positive polynomials on compact…

Algebraic Geometry · Mathematics 2024-01-18 Konrad Schmüdgen

These notes aim at providing a complete and systematic account of some foundational aspects of algebraic supergeometry, namely, the extension to the geometry of superschemes of many classical notions, techniques and results that make up the…

Algebraic Geometry · Mathematics 2025-04-08 Ugo Bruzzo , Daniel Hernandez Ruiperez , Alexander Polishchuk

We study positive bilinear forms on a Hilbert space which are neither not necessarily bounded nor induced by some positive operator. We show when different families of bilinear forms can be described as a generalized effect algebra. In…

Mathematical Physics · Physics 2015-06-15 A. Dvurečenskij , J. Janda

The aim of this article is to describe a class of *-algebras that allows to treat well-behaved algebras of unbounded operators independently of a representation. To this end, Archimedean ordered *-algebras (*-algebras whose real linear…

Operator Algebras · Mathematics 2021-08-20 Matthias Schötz

We consider the dual space of linear groups over Dynkinian and Euclidean algebras, i.e. finite dimensional algebras derived equivalent to the path algebra of Dynkin or Euclidean quiver. We prove that this space contains an open dense subset…

Representation Theory · Mathematics 2015-01-27 Viktor Bekkert , Yuriy Drozd , Vyacheslav Futorny

If one wishes to define a complete Leibniz algebra in such a way as to extend the notion of a complete Lie algebra, two distinct definitions can be found in the current literature. Since biderivations on complete Lie algebras have already…

Rings and Algebras · Mathematics 2025-10-21 Alfonso Di Bartolo , Francesco Paolo Di Fatta , Gianmarco La Rosa

A bialgebra is a structure which is simultaneously an algebra and a coalgebra, such that the algebraic and coalgebraic parts are "compatible". Bialgebras are normally studied over a field or commutative ring. In this paper, we show how to…

Rings and Algebras · Mathematics 2009-10-30 James Worthington

We give an affirmative answer to the question whether there exist Lie algebras for suitable closed subgroups of the unitary group $U(\mathcal{H})$ in a Hilbert space $\mathcal{H}$ with $U(\mathcal{H})$ equipped with the strong operator…

Operator Algebras · Mathematics 2017-08-23 Hiroshi Ando , Yasumichi Matsuzawa

We study a physically motivated representation of an algebra of operators in gravitational and non gravitational theories called the covariant representation of an algebra. This is a representation where the symmetries of the operator…

High Energy Physics - Theory · Physics 2023-08-29 Eyoab Bahiru