Intertwining operators for L 2(E)

Let (E,Q) be a finite dimensional quadratic vector space over a finite field. For the natural representation -π of the isometry group G of (E,Q) in the space L ²(E) of all complex valued functions on E, we analyse when the intertwining algebra of π is generated by just one averaging operator.     

Calabi conjecture on hyperbolic affine hyperspheres (2)

Research supported by the Alexander von Humboldt-Stiftung, the National Natural Science Foundation of China, the Science Foundation of the Educational Committee of China     

Некоторые вопросы теории приближения в пространствах L p(x) (E)

Some aspects of approximation theory are studied in the paper for the spaces of integrable functions with variable exponent. In particular, necessary and suffcient conditions on the variable exponent are established that guarantee the basis property of the trigonometric system in the corresponding normed spaces. Namely, these conditions require that the periodic variable exponent p(x) > 1 satisfy the Dini-Lipschitz condition.     

E.Ghys猜想的注记

通过类比自治动力系统中拓扑熵指数收敛的定义,给出了非自治拓扑熵指数收敛的定义及非自治Lipschitz系统中E.Ghys猜想成立的充分条件与必要条件,推广了自治动力系统中的相关结论.     

Gal(E/F)与Gal(L(E)/L(F))的同构

Let E be a field of finite extension of a perfect field F. We show that Gal(E/F) is isomorphic to Gal(L(E)/L(F)).     

A Bellman function proof of the L 2 bump conjecture

We approach the problem of finding the sharp sufficient condition for boundedness of all two weight Calderón-Zygmund operators. We solve this problem in L ² by writing a formula for a Bellman function of the problem.     

Quasi-symmetric 2-(31, 7, 7) designs and a revision of Hamada's conjecture

It is proved by use of the classification of the doubly even (32, 16) codes, that in addition to the design formed by the planes in PG(4, 2), there are exactly four other nonisomorphic quasi-symmetric 2-(31, 7, 7) designs, and they all have 2-rank 16. This shows that the “only if” part of the following conjecture due to Hamada, is not true in general: “If N(D) is an incidence matrix of a design D with the parameters of a design G defined by the flats of a given dimension in PG(t, q) or AG(t, q), then rank_q N(D) ⩾ rank_q N(G), with equality if and only if D is isomorphic with G.” The five quasi-symmetric 2-(31, 7, 7) designs are extendable to nonisomorphic 3-(32, 8, 7) designs having 2-rank 16, one of which is formed by the 3-flats in AG(5, 2), thus the designs arising from a finite affine geometry also are not characterized by their ranks in general. A quasi-symmetric 2-(45, 9, 8) design yielding a pseudo-geometric strongly regular graph with parameters (r, k, t) = (15, 10, 6) is also constructed on the base of the known extremal doubly even (48, 24) code.     

弱(L1,L2)-BLD映射的正则性

本文首先将文[1]中的BLD映射推广为弱(L1,L2)-BLD映射,并证明了如下正则性结果存在两个可积指数p1=p1(n,L1,L2)＜n＜q1=q1(n,L1,L2),使得对任意弱(L1,L2)-BLD映射,∈W1(Ω,Rn),都有,∈(Ω,Rn),即,为(L1,L2)-BLD映射.     

L（1, 2）-edge-labelings for lattices

For a graph G and two positive integers j and k, an m-L(j, k)-edge-labeling of G is an assignment on the edges to the set {0, 1, 2,..., m}, such that adjacent edges which receive labels differ at least by j, and edges which are distance two apart receive labels differ at least by kThe λ j,k-number of G is the minimum m such that an m-L(j, k)-edge-labeling is admitted by GIn this article, the L(1, 2)-edge-labeling for the hexagonal lattice, the square lattice and the triangular lattice are studied, and the bounds for λ j,k-numbers of these graphs are obtained.     

A Note on L（2, 1）-labelling of Trees

An L(2,1)-labelling of a graph G is a function from the vertex set V (G) to the set of all nonnegative integers such that |f(u) f(v)| ≥ 2 if d G (u,v)=1 and |f(u) f(v)| ≥ 1 if d G (u,v)=2.The L(2,1)-labelling problem is to find the smallest number,denoted by λ(G),such that there exists an L(2,1)-labelling function with no label greater than it.In this paper,we study this problem for trees.Our results improve the result of Wang [The L(2,1)-labelling of trees,Discrete Appl.Math.154 (2006) 598-603].     

退化弱(L1,L2)-BLD映射的正则性

本文给出空间退化的弱(L1,L2)-BLD映射的定义.利用Hodge分解,弱逆Holder不等式等工具,证明了其正则性结果对任意满足0＜L2lnl/2l2n+l×100n2[23l/2.(24l+n+1)](l-q1)＜1的q1,都存在可积指数p1=p1(n,l,q1,L1,L2)＞l,使得对任意退化的弱(L1,L2)-BLD映射f∈W1,q1 loc(Ω,Rn),都有f∈W1,p1 loc (Ω,Rn),即f为通常意义下的退化的(L1,L2)-BLD映射.     

退化弱(L1,L2)-BLD映射的正则性

本文给出空间退化的弱(L1,L2)-BLD映射的定义.利用Hodge分解,弱逆Holder不等式等工具,证明了其正则性结果:对任意满足Ol,使得对任意退化的弱(L1,L2)-BLD映射f∈Wloc1,q1(Ω,Rn),都有f∈Wloc1,p1(Ω,Rn),即f为通常意义下的退化的(L1,L2)-BLD映射.     

SL(2,R)上一类极大算子的(H∞,s1,L1)型

本文我们引入了函数类B_δ(G//K)={φ∈L¹(G//K)||φ(t)|≤Δ^-1(t)(1+t)^1-δ,δ>0),对f∈L^p(G//K),1≤p≤∞,和极大算子(?),证明了这类算子是(H_∞,s¹,L¹)型的.     

The resolution of the bounded L2 curvature conjecture in general relativity

This paper reports on the recent proof of the bounded L² curvature conjecture. More precisely we show that the time of existence of a classical solution to the Einstein-vacuum equations depends only on the L²-norm of the curvature and a lower bound of the volume radius of the corresponding initial data set.     

q-形变Lévy-Meixner过程的重整化矩(英文)

本文研究了q-形变Lévy-Meixner分布的重整化矩问题.利用集合划分的方法,获得了这种重整化矩的显式表达式,并验证了它们与经典情形的一致性.