关于丢番图方程（195n）x+（28n）y=（197n）z

运用同余及元素阶的性质,证明了对任意的正整数n,丢番图方程(195n)x+(28n)y=(197n)z仅有正整数解(x, y, z)=(2,2,2)。     

Proof of Andrews' conjecture on a 4φ3 summation

We give a new proof of a ₄φ₃ summation due to G.E. Andrews and confirm another ₄φ₃ summation conjectured by him recently. Some variations of these two ₄φ₃ summations are also given.     

The maximal coarse Baum–Connes conjecture for spaces which admit a fibred coarse embedding into Hilbert space

We introduce a notion of fibred coarse embedding into Hilbert space for metric spaces, which is a generalization of Gromov?s notion of coarse embedding into Hilbert space. It turns out that a large class of expander graphs admit such an embedding. We show that the maximal coarse Baum–Connes conjecture holds for metric spaces with bounded geometry which admit a fibred coarse embedding into Hilbert space.     

Perverse equivalences and Brouéʼs conjecture

We give a new approach to the construction of derived equivalences between blocks of finite groups, based on perverse equivalences, in the setting of Broué?s abelian defect group conjecture. We provide in particular local and global perversity data describing the principal blocks and the derived equivalences for a number of finite simple groups with Sylow subgroups elementary abelian of order 9. We also examine extensions to automorphism groups in a general setting.     

Deformations and derived equivalences

Suppose and are block algebras of finite groups over a complete local commutative Noetherian ring whose residue field is a field of positive characteristic. We prove that a split-endomorphism two-sided tilting complex (as introduced by Rickard) for the derived categories of bounded complexes of finitely generated modules over , resp. , preserves the versal deformation rings of bounded complexes of finitely generated modules over , resp. .

     

Asymptotic stability at infinity for differentiable vector fields of the plane

Let be a differentiable (but not necessarily C¹) vector field, where σ>0 and . Denote by R(z) the real part of z∈C. If for some ?>0 and for all , no eigenvalue of DpX belongs to , then: (a) for all , there is a unique positive semi-trajectory of X starting at p; (b) it is associated to X, a well-defined number I(X) of the extended real line [−∞,∞) (called the index of X at infinity) such that for some constant vector v∈R² the following is satisfied: if I(X) is less than zero (respectively greater or equal to zero), then the point at infinity ∞ of the Riemann sphere R²∪{∞} is a repellor (respectively an attractor) of the vector field X+v.     

Construction of differential operators having Bochner-Krall orthogonal polynomials as eigenfunctions

Suppose is a sequence of polynomials orthogonal with respect to the moment functional τ=σ+ν, where σ is a classical moment functional (Jacobi, Laguerre, Hermite) and ν is a point mass distribution with finite support. In this paper, we develop a new method for constructing a differential equation having as eigenfunctions.     

关于分组化验模型的一个猜想

运用概率和微分学基本理论推导出分组化验法的适用范围,给出最佳分组的存在性证明,并提出最佳分组人数的一个猜想.     

关于D-完全一致混合超图上色数的一个结论的推广

混合超图的上、下色数的研究是超图研究中一个重要的话题.由于超图本身结构上的复杂性,近年来对超图色性的研究也近局限于对一些特殊图类的研究,其中完全一致混合超图是最为热门的图类之一.给出了D完全(C不完全)一致混合超图的概念,并运用组合数学中有关分划的思想和方法对该图类的色性进行了进一步的研究,对相关文献中给出的结论进行了推广,得到了一个较为一般化的结论.并在该定理的证明中得到并证明了一个关于混合超图C稳定集的重要论断,对超图色性研究有着重要的意义.