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Related papers: Maharam traces on von Neumann algebras

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We describe families of complete orthogonal bases of full rank matrices which span the vector spaces of square matrices. The proposed bases generalise non-trivially the Pauli matrice while shedding light on their algebraic properties.…

Rings and Algebras · Mathematics 2012-05-17 Edinah K. Gnang

We consider the variety of Filippov ($n$-Lie) algebra structures on an $(n+1)$-dimensional vector space. The group $GL_n(K)$ acts on it, and we study the orbit closures with respect to the Zariski topology. This leads to the definition of…

Rings and Algebras · Mathematics 2020-02-19 Ivan Kaygorodov , Yury Volkov

We introduce a notion of rank completion for bi-modules over a finite tracial von Neumann algebra. We show that the functor of rank completion is exact and that the category of complete modules is abelian with enough projective objects.…

Operator Algebras · Mathematics 2007-05-23 Andreas Thom

One of the most significant discrete invariants of a quadratic form $\phi$ over a field $k$ is its (full) splitting pattern, a finite sequence of integers which describes the possible isotropy behaviour of $\phi$ under scalar extension to…

Number Theory · Mathematics 2016-08-03 Stephen Scully

Let $f$ bea noncommutativepolynomial of degree $m\ge 1$ over an algebraically closed field $F$ of characteristic $0$. If $n\ge m-1$ and $\alpha_1,\alpha_2,\alpha_3$ are nonzero elements from $F$ such that $\alpha_1+\alpha_2+\alpha_3=0$,…

Rings and Algebras · Mathematics 2023-02-13 Matej Brešar , Peter Šemrl

Let ${\bf M}_n(\mathbb{F})$ be the algebra of $n\times n$ matrices over an arbitrary field $\mathbb{F}$. We consider linear maps $\Phi: {\bf M}_n(\mathbb{F}) \rightarrow {\bf M}_r(\mathbb{F})$ preserving matrices annihilated by a fixed…

Functional Analysis · Mathematics 2023-02-23 Chi-Kwong Li , Ming-Cheng Tsai , Ya-Shu Wang , Ngai-Ching Wong

We show that singular Riemannian foliations, or, more generally, manifold submetries, defined on a compact normal homogeneous space, have algebraic nature. Moreover, in this case there exists a one-to-one correspondence between algebras of…

Differential Geometry · Mathematics 2025-12-19 Samuel Lin , Ricardo A. E. Mendes , Marco Radeschi

While not obvious from its initial motivation in linear algebra, there are many context where iterated traces can be defined. In this paper we prove a very general theorem about iterated 2-categorical traces. We show that many…

Algebraic Topology · Mathematics 2022-08-10 Jonathan A. Campbell , Kate Ponto

We introduce the notion of biexactness for general von Neumann algebras, naturally extending the notion from group theory. We show that biexactness implies solidity for von Neumann algebras, and that many of the examples of solid von…

Operator Algebras · Mathematics 2023-09-20 Changying Ding , Jesse Peterson

We prove a noetherian criterion for a sequence of modules with linear maps between them. This generalizes a noetherian criterion of Gan and Li for infinite EI categories. We apply our criterion to the linear categories associated to certain…

Rings and Algebras · Mathematics 2024-10-04 Wee Liang Gan , Khoa Ta

The graded Lie algebra associated with the Nottingham group over a field of prime characteristic serves as a fundamental example of Nottingham algebras, a class of infinite-dimensional, positively graded thin algebras. This paper completes…

Rings and Algebras · Mathematics 2026-03-05 M. Avitabile , A. Caranti , S. Mattarei

The dimension of any module over an algebra of affiliated operators ${\mathcal U}$ of a finite von Neumann algebra ${\mathcal A}$ is defined using a trace on ${\mathcal A}.$ All zero-dimensional ${\mathcal U}$-modules constitute the torsion…

Rings and Algebras · Mathematics 2010-09-14 Lia Vas

We characterize the connection between closed and $\sigma$-finite measures on orthogonal projections of von Neumann algebras.

Operator Algebras · Mathematics 2007-05-23 Marjan Matvejchuk

Solving a well-known problem of Maharam, Talagrand [17] constructed an exhaustive non uniformly exhaustive submeasure, thus also providing the first example of a Maharam algebra that is not a measure algebra. To each exhaustive submeasure…

Functional Analysis · Mathematics 2016-08-10 Zikica Perovic , Boban Velickovic

Let $F/F_0$ be a quadratic extension of totally real number fields, and let $E$ be an elliptic curve over $F$ which is isogenous to its Galois conjugate over $F_0$. A quadratic extension $M/F$ is said to be almost totally complex (ATC) if…

Number Theory · Mathematics 2012-04-17 Xavier Guitart , Victor Rotger , Yu Zhao

Extensions of one-parameter operator semigroups on Archimedean vector lattices to their order/ru-completions are studied. Existence and uniqueness of the extension to the ru-completion is established in the class of positive semigroups. An…

Functional Analysis · Mathematics 2024-12-24 Eduard Emelyanov

For a positive linear map F and a normal matrix N, we show that |F(N)| is bounded by some simple linear combinations in the unitary orbit of F(|N|). Several elegant sharp inequalities are derived, especially for the Schur product.

Functional Analysis · Mathematics 2020-06-18 Jean-Christophe Bourin , Eun-Young Lee

Permutation rational functions over finite fields have attracted high interest in recent years. However, only a few of them have been exhibited. This article studies a class of permutation rational functions constructed using trace maps on…

Number Theory · Mathematics 2024-01-01 Ruikai Chen , Sihem Mesnager

We investigate surjective isometries between projection lattices of two von Neumann algebras. We show that such a mapping is characterized by means of Jordan $^*$-isomorphisms. In particular, we prove that two von Neumann algebras without…

Operator Algebras · Mathematics 2018-10-23 Michiya Mori

The aim of this note is to define certain sheaves of vertex algebras on smooth manifolds. For each smooth complex algebraic (or analytic) manifold $X$, we construct a sheaf $\Omega^{ch}_X$, called the {\bf chiral de Rham complex} of $X$. It…

Algebraic Geometry · Mathematics 2009-10-31 Fyodor Malikov , Vadim Schechtman , Arkady Vaintrob