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Related papers: A refined nc Oka-Weil theorem

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A proof using the theory of completely positive maps is given to the fact that if $A \in M_2$, or $A \in M_3$ has a reducing eigenvalue, then every bounded linear operator $B$ with $W(B) \subseteq W(A)$ has a dilation of the form $I \otimes…

Functional Analysis · Mathematics 2019-02-07 Chi-Kwong Li , Yiu-Tung Poon

Let $X$ be a compact normal K\"ahler space whose canonical sheaf is a rank-one free $\mathcal O_X$ module and whose singularities are isolated, rational and quasi-homogeneous. We prove then that under a topological hypothesis the…

Algebraic Geometry · Mathematics 2025-07-18 Yohsuke Imagi

In this short note we present an elementary matrix-constructive proof of Quillen-Suslin theorem for Ore extensions: If $K$ is a division ring and $A:=K[x;\sigma,\delta]$ is an Ore extension, with $\sigma$ bijective, then every finitely…

Rings and Algebras · Mathematics 2018-04-10 Oswaldo Lezama , William Fajardo

This expository paper focuses on free Lie $K$-algebras and the basic PBW theorem. We argue in various ways that the basic PBW theorem is a quite close consequence of the Magnus-Witt theorems concerning free Lie algebras.

Rings and Algebras · Mathematics 2024-07-24 Gyula Lakos

In this note, as a particular case of a more general result, we obtain the following theorem: Let $\Omega\subseteq {\bf R}^n$ be a non-empty bounded open set and let $f:\overline {\Omega}\to {\bf R}^n$ be a continuous function which is…

Analysis of PDEs · Mathematics 2016-02-17 Biagio Ricceri

In this paper we develop a theory of free holomorphic functions on noncommutative Reinhardt domains generated by positive regular free holomorphic functions in n noncommuting variables. We show that the free biholomorphic classification of…

Operator Algebras · Mathematics 2011-11-15 Gelu Popescu

This article studies codimension one foliations on projective man-ifolds having a compact leaf (free of singularities). It explores the interplay between Ueda theory (order of flatness of the normal bundle) and the holo-nomy representation…

Classical Analysis and ODEs · Mathematics 2018-08-31 Benoît Claudon , Frank Loray , Jorge Pereira , Frédéric Touzet

The aim of this paper is to prove a Cayley-Hamilton-Ziebur Theorem for non-autonomous semilinear matrix differential equations. Moreover, we show the applicability of results like these to ODE theory.

Classical Analysis and ODEs · Mathematics 2023-06-21 Flank D. M. Bezerra , Lucas A. Santos

We discuss Nakamaye's Theorem and its recent extension to compact complex manifolds, together with some applications.

Algebraic Geometry · Mathematics 2019-04-04 Valentino Tosatti

The general theme of this note is illustrated by the following theorem: Theorem 1. Suppose $K$ is a compact set in the complex plane and 0 belongs to the boundary $\partial K$. Let ${\cal A}(K)$ denote the space of all functions $f$ on $K$…

Functional Analysis · Mathematics 2016-09-07 N. V. Rao

In this paper we study Chaplygin's Reducibility Theorem and extend its applicability to nonholonomic systems with symmetry described by the Hamilton-Poincare-d'Alembert equations in arbitrary degrees of freedom. As special cases we extract…

Mathematical Physics · Physics 2011-10-03 O. E. Fernandez , T. Mestdag , A. M. Bloch

In this paper we first offer an alternative approach to extend the original Fueter's Theorem in Dunkl-Clifford analysis to a version of the higher order case. Then this result is used to prove a generlized version of Fueter's Theorem with…

Complex Variables · Mathematics 2011-02-11 Shanshan Li , Minggang Fei

We prove a Slice Theorem around closed leaves in a singular Riemannian foliation, and we use it to study the $C^\infty$-algebra of smooth basic functions, generalizing to the inhomogeneous setting a number of results by G.~Schwarz. In…

Differential Geometry · Mathematics 2018-02-16 Ricardo Mendes , Marco Radeschi

This paper contains the constructions of a real manifold version of relative K-theory, and of an extension of Karoubi's multiplicative K-theory suggested by U. Bunke (which I call ``free multiplicative K-theory'' in the sequel).…

Differential Geometry · Mathematics 2007-05-23 Alain Berthomieu

Let $\phi \in \mbox{Out}(F_n)$ be a free group outer automorphism that can be represented by an expanding, irreducible train-track map. The automorphism $\phi$ determines a free-by-cyclic group $\Gamma=F_n \rtimes_\phi \mathbb Z,$ and a…

Geometric Topology · Mathematics 2014-03-04 Yael Algom-Kfir , Eriko Hironaka , Kasra Rafi

This note provides some technical support to the proof of a result of W. Winter which shows that two unital separable simple amenable ${\cal Z}$-absorbing C*-algebras with locally finite decomposition property satisfying the UCT whose…

Operator Algebras · Mathematics 2008-03-05 Huaxin Lin

We show that the group of all holomorphic automorphisms of complex affine space $\mathbb C^n$, $n>1$, and several of its subgroups satisfy the parametric Oka property with approximation and with interpolation on discrete sets.

Complex Variables · Mathematics 2017-03-30 Franc Forstneric , Finnur Larusson

We prove a refinement of Quillen's Theorem A, providing necessary and sufficient conditions for a functor to be cofinal with respect to diagrams valued in a fixed $\infty$-category. We deduce this from a general duality phenomenon for…

Category Theory · Mathematics 2025-12-17 Shai Keidar , Lior Yanovski

We introduce the notion of a homotopy of product systems, and show that the Cuntz-Nica-Pimsner algebras of homotopic product systems over N^k have isomorphic K-theory. As an application, we give a new proof that the K-theory of a 2-graph…

Operator Algebras · Mathematics 2024-08-16 James Fletcher , Elizabeth Gillaspy , Aidan Sims

The coadjoint orbits of compact Lie groups each carry a canonical (positive definite) K\"ahler structure, famously used to realize the group's irreducible representations in holomorphic sections of appropriate line bundles (Borel-Weil…

Differential Geometry · Mathematics 2022-11-30 Thomas Mason , Francois Ziegler