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Related papers: Parametrizing spaces of positive representations

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We study primitive stable representations of free groups into higher rank semisimple Lie groups and their properties. Let $\Sigma$ be a compact, connected, orientable surface (possibly with boundary) of negative Euler characteristic. We…

Geometric Topology · Mathematics 2020-04-03 Inkang Kim , Sungwoon Kim

A notion of fundamental group of spectral triples has been introduced. The notion uses a noncommutative analogue of unramified coverings. It was shown that in commutative case this fundamental group is a profinite completion of fundamental…

K-Theory and Homology · Mathematics 2007-05-23 Petr R. Ivankov , Nickolay P. Ivankov

The highly influential framework of conceptual spaces provides a geometric way of representing knowledge. Instances are represented by points in a high-dimensional space and concepts are represented by convex regions in this space. After…

Artificial Intelligence · Computer Science 2017-09-22 Lucas Bechberger , Kai-Uwe Kühnberger

In this paper, which is part of a study of positive representations of locally compact groups in Banach lattices, we initiate the theory of positive representations of finite groups in Riesz spaces. If such a representation has only the…

Functional Analysis · Mathematics 2012-06-29 Marcel de Jeu , Marten Wortel

A combinatorial property of prositive group presentations, called completeness, is introduced, with an effective criterion for recognizing complete presentations, and an iterative method for completing an incomplete presentation. We show…

Group Theory · Mathematics 2007-05-23 Patrick Dehornoy

We generalize a cohomological construction of representations due to Lusztig from the hyperspecial case to arbitrary parahoric subgroups of a reductive group over a local field, which splits over an unramified extension. We compute the…

Representation Theory · Mathematics 2019-03-15 Charlotte Chan , Alexander B. Ivanov

We here extend the well known Positive Real Lemma (also known as the Kalman-Yakubovich-Popov Lemma) to complex matrix-valued generalized positive rational function, when non-minimal realizations are considered. We then exploit this result…

Optimization and Control · Mathematics 2011-08-26 Daniel Alpay , Izchak Lewkowicz

We characterize finite-dimensional thick representations over ${\Bbb C}$ of connected complex semi-simple Lie groups by irreducible representations which are weight multiplicity-free and whose weight posets are totally ordered sets.…

Representation Theory · Mathematics 2021-11-18 Kazunori Nakamoto , Yasuhiro Omoda

Let G be a connected semisimple Lie group such that the associated symmetric space X is Hermitian and let Gamma be the fundamental group of a compact orientable surface of genus at least 2. We survey the study of maximal representations,…

Differential Geometry · Mathematics 2007-05-23 Marc Burger , Alessandra Iozzi , Francois Labourie , Anna Wienhard

These notes provide a concise introduction to the representation theory of reductive algebraic groups in positive characteristic, with an emphasis on Lusztig's character formula and geometric representation theory. They are based on the…

Representation Theory · Mathematics 2020-05-01 Joshua Ciappara , Geordie Williamson

The present paper is devoted to the projective positivity in the category of function systems, which plays a key role in the quantization problems of the operator systems. The main result of the paper asserts that every unital star-normed…

Operator Algebras · Mathematics 2023-03-23 Anar Dosi

There is a well-known correspondence between the symplectic variety of representations of the fundamental group of a punctured Riemann surface into a compact Lie group G, with fixed conjugacy classes at the punctures, and a complex variety…

Symplectic Geometry · Mathematics 2007-05-23 Jacques Hurtubise , Lisa C. Jeffrey

We introduce two new partial orders on the standard Young tableaux of a given partition shape, in analogy with the strong and weak Bruhat orders on permutations. Both posets are ranked by the major index statistic offset by a fixed shift.…

Combinatorics · Mathematics 2020-05-19 Sara C. Billey , Matjaž Konvalinka , Joshua P. Swanson

These notes transcribe a workshop about the notion of total positivity and $\Theta$-positivity and its relation to Higher Teichm\"uller Theory. $\Theta$-positivity is a notion of positivity in semisimple Lie groups and was recently…

Differential Geometry · Mathematics 2022-12-09 Xenia Flamm , Arnaud Maret

Building on earlier work, we further develop a formalism based on the mathematical theory of frames that defines a set of possible phase-space or quasi-probability representations of finite-dimensional quantum systems. We prove that an…

Quantum Physics · Physics 2009-06-23 Christopher Ferrie , Joseph Emerson

Motivated by asymptotic symmetry groups in general relativity, we consider projective unitary representations $\overline{\rho}$ of the Lie group $\mathrm{Diff}_c(M)$ of compactly supported diffeomorphisms of a smooth manifold $M$ that…

Mathematical Physics · Physics 2025-01-29 Bas Janssens , Milan Niestijl

The notions of reflection, symmetry, and positivity from quantum field theory are shown to induce a duality operation for a general class of unitary representations of Lie groups. The semisimple Lie groups which have this $c$-duality are…

Functional Analysis · Mathematics 2007-05-23 Palle E. T. Jorgensen , Gestur Ólafsson

We prove that the complex surfaces parametrizing cuboids and face cuboids, as well as their minimal resolution of singularities, have trivial fundamental group. We then compute the fundamental group of certain open smooth subvarieties of…

Algebraic Geometry · Mathematics 2024-09-18 David Jarossay , Francesco Maria Saettone , Yotam Svoray

We give a geometric interpretation of Fock--Goncharov positivity and show that bending deformations of Fuchsian representations stabilize a uniform Finsler quasi-convex disk in the symmetric space $\mathrm{PSL}_d(\mathbb…

Differential Geometry · Mathematics 2025-07-03 Pierre-Louis Blayac , Ursula Hamenstädt , Théo Marty

Let $\mathbf{G}$ be a connected reductive algebraic group over an algebraic closure $\overline{\mathbb{F}_p}$ of the finite field of prime order $p$ and let $F : \mathbf{G} \to \mathbf{G}$ be a Frobenius endomorphism with $G = \mathbf{G}^F$…

Representation Theory · Mathematics 2016-12-06 Jay Taylor