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A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,657 papers · 148 categories

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14294357 · Jun 202619922001200920172026
48 results for polyhedra rigidity

The paper proves rigidity and uniformization theorems for infinite circle patterns and convex polyhedra in hyperbolic 3-space.

problem Characterize infinite circle patterns and convex polyhedra in hyperbolic 3-space.
method Extends techniques from previous work to prove rigidity and uniformization theorems for infinite circle patterns and convex polyhedra.
result Establishes existence and rigidity of infinite regular circle patterns and convex trivalent polyhedra.

Study on polyhedra rigidity, finding non-existence of flexible weakly convex decomposable polyhedra.

problem Proving all decomposable polyhedra with vertices in convex position are infinitesimally rigid.
method Constructing explicit families of polyhedra, using the Hessian of the discrete Hilbert-Einstein functional, and searching for eigenvalues of the Hessian with Mathematica.
result Experimental evidence suggests no flexible, weakly convex and decomposable polyhedra exist.

Polyhedra's structure is uniquely defined by edge lengths and dihedral angles, even nonconvex.

problem Determining the structure of polyhedra based on edge lengths and dihedral angles.
method Proved rigidity under specific conditions in Euclidean, hyperbolic, and spherical geometries.
result Polyhedra's structure is uniquely defined by edge lengths and dihedral angles, even nonconvex.

Weakly convex polyhedra which are star-shaped with respect to one of their vertices are infinitesimally rigid. This is a partial answer to the question whether every decomposable weakly convex polyhedron is infinitesimally rigid. The proof uses a recent result of Izmestiev on the geometry of convex caps.

2007-04-22abs ↗pdf ↗

Characterizes infinite ideal polyhedra in hyperbolic 3-space and proves their existence and rigidity.

problem Characterize infinite ideal polyhedra in hyperbolic 3-space.
method Study ideal circle patterns (ICPs) and develop a uniform Ring Lemma via pointed Gromov-Hausdorff convergence.
result Establish existence and rigidity of embedded ICPs and infinite ideal polyhedra (IIP).

The main motivation here is a question: whether any polyhedron which can be subdivided into convex pieces without adding a vertex, and which has the same vertices as a convex polyhedron, is infinitesimally rigid. We prove that it is indeed the case for two classes of polyhedra: those obtained from a convex polyhedron b…

2006-06-27abs ↗pdf ↗

The paper proves a spacetime version of dihedral rigidity for cubes in 3D spacetime.

problem Proving dihedral rigidity for cubic initial data sets in 3D spacetime.
method By studying the level sets of spacetime harmonic functions and extending previous work on dihedral rigidity for prisms in hyperbolic space.
result The paper proves dihedral rigidity for cubes in 3D spacetime, extending previous results.

Let PP be a (non necessarily convex) embedded polyhedron in R3\R^3, with its vertices on an ellipsoid. Suppose that the interior of PP can be decomposed into convex polytopes without adding any vertex. Then PP is infinitesimally rigid. More generally, let PP be a polyhedron bounding a domain which is the union of p…

2003-01-28abs ↗pdf ↗

The Stoker problem, first formulated in 1968, consists in understanding to what extent a convex polyhedron is determined by its dihedral angles. By means of the double construction, this problem is intimately related to rigidity issues for 3-dimensional cone-manifolds. In a former paper, two such rigidity results were …

2009-03-27abs ↗pdf ↗

Study rigidity and volume optimization of hyperbolic polyhedra.

problem Rigidity and volume optimization of hyperbolic polyhedra.
method Analyzing decorated 1-3 type hyperbolic polyhedra and their metrics.
result Decorated 1-3 type hyperbolic polyhedra are rigid up to isometry and change of decorations.

New proof for global rigidity of vertex scaling on polyhedral surfaces.

problem Global rigidity of vertex scaling on polyhedral surfaces.
method Elementary variational proof based on continuity of eigenvalues and extension of convex functions.
result Global rigidity of vertex scaling proved without involving 3D hyperbolic geometry.

Löbell polyhedra have small systoles and are quasi-arithmetic.

problem Finding compact hyperbolic polyhedra with small systoles.
method Elementary and conceptual means to observe systole behavior, number theoretic invariants to refine results.
result Löbell polyhedra give examples of closed hyperbolic 3-manifolds with arbitrarily small systole and are quasi-arithmetic.

We study convex polyhedra in RP3\mathbb{R}\mathbb{P}^3 with all their vertices on a sphere. We do not require, in particular, that the polyhedra lie in the interior of the sphere, hence the term "weakly inscribed". Such polyhedra can be interpreted as ideal polyhedra, if we regard RP3\mathbb{R}\mathbb{P}^3 as a combinati…

2017-09-29abs ↗pdf ↗

We review several results related to the characterization of polyhedra in hyperbolic 3-space. In particular we present Rivin's theorem that gives a characterization of compact convex hyperbolic polyhedra, and Hodgson's proof of the Adreev's theorem. We also review the analogous characterization of ideal polyhedra, and …

2010-06-23abs ↗pdf ↗

In this paper we consider a class of right-angled polyhedra in three-dimensional Lobachevsky space, all vertices of which lie on the absolute. New upper bounds on volumes in terms the number of faces of the polyhedron are obtained. Volumes of polyhedra with at most 23 faces are computed. It is shown that the minimum vo…

2019-09-25abs ↗pdf ↗

This article defines a pair of combinatorial operations on the combinatorial structure of compact right-angled hyperbolic polyhedra in dimension three called decomposition and edge surgery. It is shown that these operations simplify the combinatorics of such a polyhedron, while keeping it within the class of right-angl…

2008-09-11abs ↗pdf ↗

We present a notion of mutation of hyperbolic polyhedra, analogous to mutation in knot theory, and then present a general question about commensurability of mutant pairs of polyhedra. We motivate that question with several concrete examples of mutant pairs for which commensurability is unknown. The polyhedra we conside…

2019-06-20abs ↗pdf ↗

New families of hyperbolic polyhedra yield infinitely many unique reflection groups.

problem Understanding commensurability classes of compact Coxeter polyhedra in hyperbolic spaces.
method Analyzing families of compact Coxeter polyhedra constructed by Makarov.
result Proves infinitely many commensurability classes in 4- and 5-dimensional hyperbolic spaces.

The paper solves three problems related to monostable polyhedra.

problem Three problems related to monostable polyhedra posed by Conway and Goldberg.
method General theorem describing approximations of smooth convex bodies by convex polyhedra in terms of static equilibrium points.
result Existence of a convex polyhedron with only one stable and one unstable point.

In this article we establish the relation between the spines of 3-manifolds and the polyhedra with identified faces. We do this by showing that the spines of the closed, connected, orientable 3-manifolds can be presented through polyhedra with identified faces in a very natural way. We also prove the equivalence betwee…

2012-04-16abs ↗pdf ↗

Paper solves long-standing problem of infinite ideal polyhedra in hyperbolic space.

problem Characterize infinite ideal polyhedra in hyperbolic 3-space.
method Introduced combinatorial Ricci flow for infinite ideal circle patterns.
result Proved characterization of infinite ideal circle patterns under specific conditions.

An algorithm for determining the list of smallest volume right-angled hyperbolic polyhedra in dimension 3 is described. This algorithm has been implemented on computer using the program Orb to compute volumes, and the first 825 polyhedra in the list have been determined.

2015-12-06abs ↗pdf ↗

Software finds ideal polyhedra with rational dihedral angles and volume maxima.

problem Finding ideal convex polyhedra with maximal volume in hyperbolic 3-space.
method Rivin's variational characterization and combinatorial optimization algorithms.
result Maximal volume ideal polyhedra have dihedral angles that are rational multiples of π.