Dirac’s Type Sufficient Conditions for Hamiltonicity and Pancyclicity

Let G = (V, E) be a any simple, undirected graph on n ≥ 3 vertices with the degree sequence . We consider the class of graphs satisfying the condition where , is a positive integer. It is known that is hamiltonian if θ ≤ δ. In this paper,

Hoeffding’s Inequality for Sums of Dependent Random Variables

Let \(X_1,\ldots ,X_n\) be, possibly dependent, [0, 1]-valued random variables. What is a sharp upper bound on the probability that their sum is significantly larger than their mean? In the case of independent random variables, a fundamental tool for bounding such probabilities is devised by Wassily Hoeffding. In this paper, we provide a generalisation of Hoeffding’s theorem. We obtain an estimate on the aforementioned probability that is described in terms of the expectation, with respect to convex functions, of a random variable that concentrates mass on the set \(\{0,1,\ldots ,n\}\). Our main result yields concentration inequalities for several sums of dependent random variables such as sums of martingale difference sequences, sums of k-wise independent random variables, as well as for sums of arbitrary [0, 1]-valued random variables.     

Bounds on Multivariate Kendall’s Tau and Spearman’s Rho for Zero-Inflated Continuous Variables and their Application to Insurance

Methodology and Computing in Applied Probability - In this note, we derive upper bounds on Kendall’s tau and Spearman’s rho for multivariate zero-inflated continuous variables often...     

Negatively Correlated Random Variables and Mason’s Conjecture for Independent Sets in Matroids

Mason’s Conjecture asserts that for an m-element rank r matroid the sequence is logarithmically concave, in which I _k is the number of independent k-sets of . A related conjecture in probability theory implies these inequalities provided that the set of independent sets of satisfies a strong negative correlation property we call the Rayleigh condition. This condition is known to hold for the set of bases of a regular matroid. We show that if ω is a weight function on a set system that satisfies the Rayleigh condition then is a convex delta-matroid and ω is logarithmically submodular. Thus, the hypothesis of the probabilistic conjecture leads inevitably to matroid theory. We also show that two-sums of matroids preserve the Rayleigh condition in four distinct senses, and hence that the Potts model of an iterated two-sums of uniform matroids satisfies the Rayleigh condition. Numerous conjectures and auxiliary results are included. Research supported by the Natural Sciences and Engineering Research Council of Canada under operating grant OGP0105392.     

Voronovskaja’s Theorem and Iterations for Complex Bernstein Polynomials in Compact Disks

In this paper, firstly we prove the Voronovskaja’s convergence theorem for complex Bernstein polynomials in compact disks in , centered at origin, with quantitative estimates of this convergence. Secondly, we study the approximation properties of the iterates of complex Bernstein polynomials and we prove that they preserve in the unit disk (beginning with an index) the univalence, starlikeness, convexity and spirallikeness. Received: May 5, 2007 Revised: September 14, 2007 and November 11, 2007 Accepted: November 26, 2007     

Regularity Conditions for Einstein’s Equations at Spatial Infinity

The regular finite initial value problem at spatial infinity is used to obtain regularity conditions on the freely specifiable parts of initial data sets for the vacuum Einstein equations with non-vanishing second fundamental forms. These conditions ensure that the solutions of the conformal Einstein equations extend smoothly through the sets where spatial infinity touches null infinity. For simplicity, the conformal metric of the initial data set is assumed to be analytic, although the results presented here could be extended to a setting where the conformal metric is only smooth. The analysis given here is a generalisation of the analysis of the regular finite initial value problem first carried out by Friedrich, in the case of time symmetric initial data sets. Submitted: May 12, 2009. Accepted: May 13, 2009.     

Beurling’s Phenomenon in Two Variables

In the Hardy space over the unit disk H²(D), every shift-invariant subspace M is of the form H²(D)) for some inner function by Beurlings theorem, and the reproducing kernel of M is . The fact that is inner implies that is subharmonic and has boundary value 1 almost everywhere on T. In the two variable space H²(D²), things are far more complicated and there is no similar characterization of invariant subspaces M in terms of inner functions. However, we will show in this paper an analogous phenomenon in terms of reproducing kernels, namely, is subharmonic and has boundary value 1 almost everywhere on T². The proof uses an index theorem obtained recently.     

Kobayashi’s and Teichmuller’s Metrics and Bers Complex Manifold Structure on Circle Diffeomorphisms

Given a modulus of continuity ω,we consider the Teichmuller space TC1+ω as the space of all orientation-preserving circle diffeomorphisms whose derivatives are ω-continuous functions modulo the space of Mobius transformations preserving the unit disk.We study several distortion properties for diffeomorphisms and quasisymmetric homeomorphisms.Using these distortion properties,we give the Bers complex manifold structure on the Teichm(u| ")ller space TC^1+H as the union of over all0 <α≤1,which turns out to be the largest space in the Teichmuller space of C1 orientation-preserving circle diffeomorphisms on which we can assign such a structure.Furthermore,we prove that with the Bers complex manifold structure on TC^1+H ,Kobayashi’s metric and Teichmuller’s metric coincide.     

Lu Qi-Keng’s Problem for Intersection of Two Complex Ellipsoids

In this paper we investigate the Lu Qi-Keng problem for intersection of two complex ellipsoids \(\{z \in \mathbb {C}^3 :|z_1|^2 + |z_2|^q < 1, |z_1|^2 + |z_3|^r < 1\}\).     

Fourier Method for an Over-Determined Elliptic System with Several Complex Variables

Two boundary value problems are investigated for an over-determined elliptic system with several complex variables in polydisc. Necessary and sufficient conditions for the existence of finitely many linearly independent solutions and finitely many solvability conditions are derived. Moreover, the boundary value problem for any number of complex variables is treated in a unified way and the essential difference between the case of one complex variable and that of several complex variables is revealed.     

Denjoy-Wolff theorems for Hilbert’s and Thompson’s metric spaces

We study the dynamics of fixed point free mappings on the interior of a normal, closed cone in a Banach space that are nonexpansive with respect to Hilbert’s metric or Thompson’s metric. We establish several Denjoy-Wolff type theorems which confirm conjectures by Karlsson and Nussbaum for an important class of nonexpansive mappings. We also extend and put into a broader perspective results by Gaubert and Vigeral concerning the linear escape rate of such nonexpansive mappings.     

Green’s Functional for Higher-Order Ordinary Differential Equations with General Nonlocal Conditions and Variable Principal Coefficient

Ukrainian Mathematical Journal - The method of Green’s functional is a little-known technique for the construction of fundamental solutions to linear ordinary differential equations (ODE)...     

Rosenthal’s Inequalities for Asymptotically Almost Negatively Associated Random Variables Under Upper Expectations

In this paper, the authors generalize the concept of asymptotically almost \linebreak negatively associated random variables from the classic probability space to the upper expectation space. Within the framework, the authors prove some different types of Rosenthal''s inequalities for sub-additive expectations. Finally, the authors prove a strong law of large numbers as the application of Rosenthal''s inequalities.     

Complex Euler’s groups and values of Euler’s function at complex integer Gauss points

The complex Euler group is defined associating to an integer complex number z the multiplicative group of the complex integers residues modulo z, relatively prime to z. This group is calculated for z=(3+0i) ⁿ : it is isomorphic to the product of three cyclic group or orders (8, 3 ⁿ⁻¹ and 3 ⁿ⁻¹).     

On Sarnak’s conjecture and Veech’s question for interval exchanges

Using a criterion due to Bourgain [10] and the generalization of the self-dual induction defined in [19], for each primitive permutation we build a large family of k-interval exchanges satisfying Sarnak’s conjecture, and, for at least one permutation in each Rauzy class, smaller families for which we have weak mixing, which implies a prime number theorem, and simplicity in the sense of Veech.     

Perron’s Method and Wiener’s Theorem for a Nonlocal Equation

We study the Dirichlet problem for non-homogeneous equations involving the fractional p-Laplacian. We apply Perron’s method and prove Wiener’s resolutivity theorem.     

On the Bloch Constant for Κ-Quasiconformal Mappings in Several Complex Variables

We study the Bloch constant for Κ-quasiconformal holomorphic mappings of the unit ball B of C ⁿ . The final result we prove in this paper is: If f is a Κ-quasiconformal holomorphic mappig of B into C ⁿ such that det(f′(0)) = 1, then f(B) contains a schlicht ball of radius at least where C _n > 1 is a constant depending on n only, and as n→∞. Received June 24, 1998, Accepted January 14, 1999