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Related papers: Non-discrete affine buildings and convexity

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We define for every affine Coxeter graph a certain factor group of the associated Artin group and prove that some of these groups appear as orbifold fundamental groups of moduli spaces. Examples are the moduli space of nonsingular cubic…

Algebraic Geometry · Mathematics 2007-06-13 Eduard Looijenga

This note contains some observations on abelian convexity theorems. Convexity along an orbit is established in a very general setting using Kempf-Ness functions. This is applied to give short proofs of the Atiyah-Guillemin-Sternberg theorem…

Differential Geometry · Mathematics 2018-10-09 Leonardo Biliotti , Alessandro Ghigi

The purpose of this paper is to provide an easier set of axioms for Affine $\Lambda$-Buildings by extending results of Anne Parreau on the equivalence of axioms for Euclidean buildings. In particular we give an easier set of axioms for an…

Group Theory · Mathematics 2009-09-14 Curtis D. Bennett

Abstract In this paper, we study affine bodies of revolution. This will allow us to prove that a convex body all whose orthogonal $n$-projections are affinely equivalent is an ellipsoid, provided $n\equiv 0,1, 2$ mod $4$, $n>1$ with the…

Metric Geometry · Mathematics 2020-05-06 Luis Montejano

We give an abstract definition of affine hovels which generalizes the definition of affine buildings (eventually non simplicial) given by Jacques Tits and includes the hovels built by Stephane Gaussent and the author for some Kac-Moody…

Group Theory · Mathematics 2008-10-24 Guy Rousseau

Let $\A$ be a finite dimensional vector space and $\Phi$ be a finite root system in $\A$. To this data is associated an affine poly-simplicial complex. Motivated by a forthcoming construction of connectified higher buildings, we study…

Group Theory · Mathematics 2024-11-18 Claudio Bravo , Auguste Hébert , Diego Izquierdo , Benoit Loisel

This paper deals with non-Archimedean representations of punctured surface groups in PGL(3), associated actions on Euclidean buildings (of type A2), and degenerations of real convex projective structures on surfaces. The main result is…

Geometric Topology · Mathematics 2015-04-16 Anne Parreau

We prove a rigid analytic analogue of the Artin vanishing theorem. Precisely, we prove (under mild hypotheses) that the geometric etale cohomology of any Zariski-constructible sheaf on any affinoid rigid space $X$ vanishes in all degrees…

Number Theory · Mathematics 2017-08-25 David Hansen

In this paper we will first introduce the notion of affine structures on a ringed space and then obtain several properties. Affine structures on a ringed space, arising mainly from complex analytical spaces of algebraic schemes over number…

Algebraic Geometry · Mathematics 2010-07-15 Feng-Wen An

Inspired by the Weierstrass representation of smooth affine minimal surfaces with indefinite metric, we propose a constructive process producing a large class of discrete surfaces that we call discrete affine minimal surfaces. We show that…

Differential Geometry · Mathematics 2008-04-29 Marcos Craizer , Henri Anciaux , Thomas Lewiner

In this paper, we extend the previous convergence results for the generalized alternating projection method applied to subspaces in [arXiv:1703.10547] to hold also for smooth manifolds. We show that the algorithm locally behaves similarly…

Optimization and Control · Mathematics 2024-04-10 Mattias Fält , Pontus Giselsson

Finite convex geometries are combinatorial structures. It follows from a recent result of M.\ Richter and L.G.\ Rogers that there is an infinite set $T_{rr}$ of planar convex polygons such that $T_{rr}$ with respect to geometric convex…

Combinatorics · Mathematics 2016-08-24 Gábor Czédli , János Kincses

In this note we study in a finite dimensional Lie algebra ${\mathfrak g}$ the set of all those elements x for which the closed convex hull of the adjoint orbit contains no affine lines; this contains in particular elements whose adjoint…

Representation Theory · Mathematics 2021-10-15 Karl-Hermann Neeb , Daniel Oeh

In this paper, we give a general group-theoretic construction of affine $\RR$-buildings, and more generally, of affine $\Lambda$-buildings, associated to semisimple Lie groups over nonarchimedean real closed fields. The construction of…

Differential Geometry · Mathematics 2007-05-23 Linus Kramer , Katrin Tent

Given a semisimple group over a complete non-Archimedean field, it is well known that techniques from non-Archimedean analytic geometry provide an embedding of the corresponding Bruhat-Tits builidng into the analytic space associated to the…

Algebraic Geometry · Mathematics 2021-09-14 Bertrand Rémy , Amaury Thuillier , Annette Werner

In the paper, properties of antisymmetric orbit functions are reviewed and further developed. Antisymmetric orbit functions on the Euclidean space $E_n$ are antisymmetrized exponential functions. Antisymmetrization is fulfilled by a Weyl…

Mathematical Physics · Physics 2008-04-24 Anatoliy Klimyk , Jiri Patera

The architecture of infinite structures with non-crystallographic symmetries can be modeled via aperiodic tilings, but a systematic construction method for finite structures with non-crystallographic symmetry at different radial levels is…

Mathematical Physics · Physics 2015-08-19 Reidun Twarock , Motiejus Valiunas , Emilio Zappa

We study convex subsets of buildings, discuss some structural features and derive several characterizations of buildings.

Metric Geometry · Mathematics 2007-05-23 Andreas Balser , Alexander Lytchak

We give a classification of generic coadjoint orbits for the group of area-preserving diffeomorphisms of a closed non-orientable surface. This completes V. Arnold's program of studying invariants of incompressible fluids in 2D. As an…

Symplectic Geometry · Mathematics 2024-04-09 Anton Izosimov , Boris Khesin , Ilia Kirillov

Let $G$ be a Lie group, $\Gamma\subset G$ a discrete subgroup, $X=G/\Gamma$, and $f$ an affine map from $X$ to itself. We give conditions on a submanifold $Z$ of $X$ guaranteeing that the set of points $x\in X$ with $f$-trajectories…

Dynamical Systems · Mathematics 2021-01-19 Jinpeng An , Lifan Guan , Dmitry Kleinbock