Bandt-Wang的一个定理的新证明

讨论格自仿Tile的边界结构,得到平面格自仿Tile的边界为简单闭曲线的一个充分条件;作为应用,给出Bandt-Wang的一个定理的新证明.     

A New Proof of Bartholdi's Theorem

We give a new proof of Bartholdi's theorem for the Bartholdi zeta function of a graph. Supported by Grant-in-Aid for Science Research (C)     

A New Proof of Calabi-Yau＇s Theorem

We give a new proof of Calabi-Yau＇s theorem on the volume growth of Riemannian manifolds with non-negative Ricci curvature.     

整数偶序列为蕴含强连通的Beineke－Harary判准

一个由ｎ个非负整数有序对构造的序列是有向可图的,如果它是某个有向图的度序列．一个有向可图序列是蕴含强连通的,如果它是某个强连通有向图的度序列．Ｂｅｉｎｅｋｅ和Ｈａｒａｒｙ给出了一个有向可图序列为蕴含强连通的判准．Ｂｅｉｎｅｋｅ－Ｈａｒａｒｙ判准的充分性证明是“相当长”的（见［１］）．本文的目的是给出Ｂｅｉｎｅｋｅ－Ｈａｒａｒｙ判准的充分性的一个简短证明．     

A New Proof of Spinks' Theorem

Skew lattices form a class of non-commutative lattices. Spinks' Theorem [Matthew Spinks, On middle distributivity for skew lattices, ] states that for symmetric skew lattices the two distributive identities and are equivalent. Up to now only computer proofs of this theorem have been known. In the present paper the author presents a direct proof of Spinks' Theorem. In addition, a new result is proved showing that the assumption of symmetry can be omitted for cancellative skew lattices.     

A New Proof of Calabi-Yau's Theorem

We give a new proof of Calabi-Yau's theorem on the volume growth of Rie- mannian manifolds with non-negative Ricci curvature.     

柯西积分定理的一个新证明

我们利用调和分析的方法给出了柯西积分定理的一个新的证明,我们的证明比古莎所给出的证明简单.     

A New Proof of Ko Chao's Theorem

We present a new proof of the well-known Ko Chao theorem.     

A New Proof for the Interpolating Theorem

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Erd?s-Ginzburg-Ziv定理的一个新证明

本文给出Erd?s-Ginzburg-Ziv定理的一个新证明     

反正切相加定理的一种新证法

利用微分方程给出了反正切相加定理的一种新证法,该方法可直接确定反正切相加定理中函数ε(x,y)的连续域以及函数在域内的取值.     

Leray-Schauder不动点定理的一个新证明

给出Leray-Schauder不动点定理的一个新证明.我们首先给出集值映射的焊接引理,利用集值映射的焊接引理和Kakutani不动点定理证明Leray-Schauder不动点定理,并证明Leray-Schauder不动点定理与Brouwer不动点定理等价.     

A New Simple Proof of the Aztec Diamond Theorem

The Aztec diamond of order n is the union of lattice squares in the plane intersecting the square \(|x|+|y|<n\). The Aztec diamond theorem states that the number of domino tilings of this shape is \(2^{n(n+1)/2}\). It was first proved by Elkies et al. (J. Algebraic Comb. 1(2):111–132, 1992). We give a new simple proof of this theorem.     

A Proof of Sharkovsky's Theorem

This paper presents a variation on the standard directed graph proof. This variation makes use of the natural representation of the symmetric group given by one-dimensional maps.     

A Simple Proof of a Theorem of Whyte

Kevin Whyte showed that all Baumslag–Solitar groups BS(p,q) with 1 < p < q are quasi-isometric [Whyte, K., Geom. Funct. Anal. 11 (2001), 1327–1343]. We provide an elementary geometric proof.     

Erd(o)s-Ginzburg-Ziv定理的一个新证明

本文给出Erdos-Ginzburg-Ziv定理的一个新证明     

A Simple Proof for a Spectral Factorization Theorem

It is shown using simple methods that the transform Z(z), z C, of the coefficient sequence of the Wold decomposition ofany full-rank wide-sense stationary purely non-deterministicstochastic process satisfies (i) Z(z) H² (D) and (ii) Z^–1(z) H(D). Further it is shown that all spectral factors satisfying(i) and (ii) are equal up to right multiplication by orthogonalmatrices, and that among these the normalized (Z(0) =I) spectralfactors are equal to the transform of the Wold decomposition.An elementary proof of Youla's Theorem is then given togetherwith a simple proof that the rows of a Cholesky factor of abanded block Toeplitz matrix converge to the coefficients ofa stable matrix polynomial. Computer and Automation Institute of the Hungarian Academyof Sciences, Budapes, Hungary.