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Related papers: Extremal norms for positive linear inclusions

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We look at a class of transcendental real numbers xi which, together with their square, satisfy some extremal property of simultaneous approximation by rational numbers with the same denominator. We give a sufficient condition for such a…

Number Theory · Mathematics 2013-01-07 Damien Roy

We construct irreducible unitary representations of a finitely generated free group which are weakly contained in the left regular representation and in which a given linear combination of the generators has an eigenvalue. When the…

Operator Algebras · Mathematics 2007-05-23 William L. Paschke

Consensus is a well-studied problem in distributed sensing, computation and control, yet deriving useful and easily computable bounds on the rate of convergence to consensus remains a challenge. This paper discusses the use of seminorms for…

Systems and Control · Electrical Eng. & Systems 2025-08-29 Ron Ofir , Ji Liu , A. Stephen Morse , Brian D. O. Anderson

We provide polynomial lower bounds for residual finiteness of residually finite, finitely generated solvable groups that admit infinite order elements in the Fitting subgroup of strict distortion at least exponential. For this class of…

Group Theory · Mathematics 2019-12-03 Mark Pengitore

We develop the representation theory of a finite semigroup over an arbitrary commutative semiring with unit, in particular classifying the irreducible and minimal representations. The results for an arbitrary semiring are as good as the…

Rings and Algebras · Mathematics 2010-04-13 Zur Izhakian , John Rhodes , Benjamin Steinberg

It is shown that the use of extended sets of irreducible representations of the Lorentz group opens new possibilities for the theory of relativistic wave equations from the point of view of the space-time description of both the internal…

General Physics · Physics 2018-04-03 V. A. Pletyukhov

The core arguments used in various proofs of the extremal principle and its extensions as well as in primal and dual characterizations of approximate stationarity and transversality of collections of sets are exposed, analyzed and refined,…

Optimization and Control · Mathematics 2022-06-17 Hoa T. Bui , Alexander Y. Kruger

In this paper we introduce new notions of local extremality for finite and infinite systems of closed sets and establish the corresponding extremal principles for them called here rated extremal principles. These developments are in the…

Optimization and Control · Mathematics 2011-02-28 Boris S. Mordukhovich , Hung M. Phan

We give new, explicit and asymptotically sharp, lower bounds for dimensions of irreducible modular representations of finite symmetric groups.

Representation Theory · Mathematics 2019-09-10 Alexander Kleshchev , Lucia Morotti , Pham Huu Tiep

Let E be the Engel group and D be a rank 2 bracket generating left invariant distribution with a Lorentzian metric, which is a nondegenerate metric of index 1. In this paper, we first prove that timelike normal extremals are locally…

Differential Geometry · Mathematics 2015-07-28 Andrey Ardentov , Tiren Huang , Yuri L. Sachkov , Xiaoping Yang

We consider epimorphisms and several variant notions -- split, effective, regular, strong, and extremal -- and determine which of these coincide in the metric coarse and coarsely Lipschitz categories. In particular, we characterise extremal…

Metric Geometry · Mathematics 2025-12-16 Robert Tang

We study the possibility of applying a finite-dimensionality argument in order to address parts of the Baum-Connes conjecture for finitely generated linear groups. This gives an alternative approach to the results of Guentner, Higson, and…

Geometric Topology · Mathematics 2007-05-23 Dmitry Matsnev

We classify globally irreducible representations of alternating groups and double covers of symmetric and alternating groups. In order to achieve this classification we also completely characterise irreducible representations of such groups…

Representation Theory · Mathematics 2024-10-29 Matthew Fayers , Lucia Morotti

Extremal length is a classical tool in 1-dimensional complex analysis for building conformal invariants. We propose a higher-dimensional generalization for complex manifolds and provide some ideas on how to estimate and calculate it. We…

Complex Variables · Mathematics 2020-06-26 Tommaso Pacini

We introduce the notion of uniform exactness, or uniform amenability at infinity, for discrete groups and prove it for a wide class of groups containing free groups and their limit groups. This shows a novel strong convergence phenomenon…

Group Theory · Mathematics 2026-05-01 Narutaka Ozawa

Tensor product of irreducible modules of highest weight over a semi-simple quantum group is semi-simple if and only if a natural contravariant form is non-degenerate when restricted to the span of singular vectors. We express this…

Quantum Algebra · Mathematics 2019-11-26 Andrey Mudrov

We consider a left-invariant (sub-)Lorentzian structure on a Lie group. We assume that this structure is defined by a closed convex salient cone in the corresponding Lie algebra and a continuous antinorm associated with this cone. We derive…

Optimization and Control · Mathematics 2024-06-18 A. V. Podobryaev

An extension of the finite and infinite Lie groups properties of complex numbers and functions of complex variable is proposed. This extension is performed exploiting hypercomplex number systems that follow the elementary algebra rules. In…

Mathematical Physics · Physics 2007-05-23 Francesco Catoni , Paolo Zampetti

We define basic notions in the category of conic representations of a topological group and prove elementary facts about them. We show that a conic representation determines an ordinary dynamical system of the group together with a…

Dynamical Systems · Mathematics 2019-03-25 Matan Tal

We give a necessary and sufficient condition for extremality of a supermodular function based on its min-representation by means of (vertices of) the corresponding core polytope. The condition leads to solving a certain simple linear…

Combinatorics · Mathematics 2016-06-28 M. Studený , T. Kroupa