Chiral Polyhedra in Ordinary Space, I

Chiral polyhedra in ordinary euclidean space E³ are nearly regular polyhedra; their geometric symmetry groups have two orbits on the flags, such that adjacent flags are in distinct orbits. This paper completely enumerates the discrete infinite chiral polyhedra in E³ with finite skew faces and finite skew vertex-figures. There are several families of such polyhedra of types {4,6}, {6,4} and {6,6}. Their geometry and combinatorics are discussed in detail. It is also proved that a chiral polyhedron in E³ cannot be finite. Part II of the paper will complete the classification of all chiral polyhedra in E³. All chiral polyhedra not described in Part I have infinite, helical faces and again occur in families. So, in effect, Part I enumerates all chiral polyhedra in E³ with finite faces.     

Polyhedra without diagonals II

It is shown that no polyhedron without diagonals exists with five vertices.      

Regular Polytopes in Ordinary Space

The three aims of this paper are to obtain the proof by Dress of the completeness of the enumeration of the Grünbaum—Dress polyhedra (that is, the regular apeirohedra, or apeirotopes of rank 3) in ordinary space E ³ in a quicker and more perspicuous way, to give presentations of those of their symmetry groups which are affinely irreducible, and to describe all the discrete regular apeirotopes of rank 4 in E ³ . The paper gives a complete classification of the discrete regular polytopes in ordinary space. Received June 6, 1996, and in revised form October 28, 1996.     

Translations and Associated Dirichlet Polyhedra in Complex Hyperbolic Space

We study a nonidentity transvection (i.e. (strictly) hyperbolic isometry) or nonidentity Heisenberg translation f of complex hyperbolic space H ⁿ and a Dirichlet polyhedron P of the cyclic group f. We have four main results: (a) If z & in H ⁿ and the axis of a nonidentity transvection are not complex collinear, then, roughly speaking, any two distinct 'naturally arising' geodesics passing through z are not complex collinear. (b) If g is also a transvection or Heisenberg translation of H ⁿ and z & in H ⁿ such that f(z)=g(z) and f ^–1(z)=g ^–1(z), then f=g. (c) We classify all this kind of polyhedra up to congruence in H ⁿ. (d) We obtain an equivalent condition for P to be cospinal (which means that the complex spines of the two sides of P coincide) in terms of the distance of the spines of the two sides of P.     

Differences of Polyhedra in Matrix Space and Their Applications to Nonsmooth Analysis

Formulas of the differences of polyhedra in matrix space are proposed. Based on these formulas, the differences of polyhedra can be calculated by solving systems of linear inequalities. A modified algorithm for calculating one element of the differences is presented also. The motivation for this work is to compute the Clarke generalized Jacobian, the B-differential, and one of their elements via the quasidifferential. Applications to Newton methods for solving nonsmooth equations are discussed.This project was sponsored by the Shanghai Education Committee, Grant 04EA01, by the Education Ministry of China, and by the Shanghai Government, Grant T0502. The author thanks two anonymous referees and Professor F. Giannessi for valuable suggestions and comments.     

Chip-Firing,Antimatroids, and Polyhedra

Starting from the chip-firing game of Björner and Lovász we consider a generalization to vector addition systems that still admit algebraic structures as sandpile group or sandpile monoid. Every such vector addition language yields an antimatroid. We show that conversely every antimatroid can be represented this way. The inclusion order on the feasible sets of an antimatroid is an upper locally distributive lattice. We characterize polyhedra, which carry an upper locally distributive structure and show that they can be modelled by chip-firing games with gains and losses. At the end we point out a connection to a membership problem discussed by Korte and Lovász.     

Arithmetical Semigroups Related to Trees and Polyhedra,II — Maps on Surfaces

This paper extends recent investigations by Arnold Knopfmacher and John Knopfmacher [10] of asymptotic enumeration questions concerning finite graphs, trees and polyhedra. The present emphasis is on the counting of non‐isomorphic maps of not necessarily connected finite graphs on arbitrary surfaces. A significant aid towards this goal is provided by an extended abstract prime number theorem, based partly on more delicate tools of analysis due to W. K. Hayman [8].     

Banach空间Volterra型二阶微分积分方程两点边值问题的唯一解

在一般序Banach空间中研究了不连续的二阶微分方程两点边值问题解的存在唯一性,给出了解的显式迭代列和误差估计式.     

Integral Representations in Linearly Convex Polyhedra

We introduce the notion of mixed Levian (Levi determinant) of a system of k Hermitian and k linear forms. In terms of these Levians we obtain an integral formula for holomorphic functions in linearly convex polyhedra.Original Russian Text Copyright © 2005 Krivokolesko V. P. and Tsikh A. K.The first author was supported by a grant of the President of the Russian Federation and the State Maintenance Program for the Leading Scientific Schools of the Russian Federation (Grant NSh-1212.2003.1); the second author was supported by the Ministry for Education of the Russian Federation (St. Petersburg, Grant 02-1-138).__________Translated from Sibirskii Matematicheskii Zhurnal, Vol. 46, No. 3, pp. 579–593, May–June, 2005.     

Characterization of Domains of Self-Adjoint Ordinary Differential Operators II

We characterize the self-adjoint domains of general even order linear ordinary differential operators in terms of real-parameter solutions of the differential equation. This for endpoints which are regular or singular and for arbitrary deficiency index. This characterization is obtained from a new decomposition of the maximal domain in terms of limit-circle solutions. These are the solutions which contribute to the self-adjoint domains in analogy with the celebrated Weyl limit-circle solutions in the second order Sturm–Liouville case. As a special case we obtain the previously known characterizations when one or both endpoints are regular.     

A Property of the Normal Subdivision of Space into Polyhedra Induced by a Packing of Compact Bodies

The notion of densest packing of compact bodies, as introduced by Hilbert, is generalized to the notion of non-completable packing of compact bodies. The bodies in the packing are equipped by marked points. Conditions on the arrangement of the marked points in the packing generalize those for the Delone-Aleksandrov point system. It is proved that the number of combinatorially distinct Voronoi-Dirichlet regions in the Euclidean n-space that correspond to the marked points is finite. Bibliography: 5 titles. __________ Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 299, 2003, pp. 38–41.     

Space–Time Chaos,Critical Phenomena,and Bifurcations of Solutions of Infinite-Dimensional Systems of Ordinary Differential Equations

We study infinite-dimensional systems of ordinary differential equations having applications in some popular and important physical problems. The appearance of infinite-dimensional space–time chaos is considered, namely, the bifurcations and critical phenomena that occur in the phase space of the systems and explain some physical problems are described.     

Banach空间中二阶非线性常微分方程周期边值问题

在Banach空间中利用上下解方法与增算子不动点定理,研究了含间断项的二阶非线性常微分方程周期边值问题的最大解、最小解的存在性,推广和改进了现有的结果．     

A Variational Principle in Krein Space II

Let A be a self-adjoint operator in a Krein space Under certain natural assumptions, it is shown precisely which real eigenvalues of A can be given a max-inf characterization generalizing the usual one in Hilbert space. This result unifies several approaches in the recent literature.