关于偶数Goldbach数的均值性质

设D(n)表示方程n=p1+p2的解数,其中p1,p2为奇素数,若D(n)>0,则我们称n为偶数G o ldbach数.主要目的是利用初等和解析方法从两个不同的角度来研究偶数G o ldbach数的均值性质,并给出了两个相同的渐近公式,从而为进一步证明偶数G o ldbach猜想的正确性提供了有力的证据.     

一个关于上凸密度猜测的否定回答

Let E be a self-similar set satisfying the open set condition. Professor Xu conjectures in his doctoral degree thesis that if H^8（E） 〈｜E｜^8, then for any x ∈ E, the inequality ^-D^3C（E,x）〉H^8（E）/｜E｜^8holds, where 3 = dimH（E）. The above conjecture is negatively answered in this＇paper.     

A Remark on Jesmanowicz' Conjecture for the Non-coprimality Case

Let a, b, c be relatively prime positive integers such that a2+ b2= c2. Je′smanowicz'conjecture on Pythagorean numbers states that for any positive integer N, the Diophantine equation(aN)x+(b N)y=(cN)zhas no positive solution(x, y, z) other than x = y = z = 2. In this paper, we prove this conjecture for the case that a or b is a power of 2.     

The Overfull Conjecture and the Conformability Conjecture

In this paper we show that under some fairly general conditions the Overfull Conjecture about the chromatic index of a graph G implies the Conformability Conjecture about the total chromatic number of G. We also show that if G has even order and high maximum degree, then G is conformable unless the deficiency is very small.     

Minimum Norm Solution to the Absolute Value Equation in the Convex Case

In this paper, we give an algorithm to compute the minimum norm solution to the absolute value equation (AVE) in a special case. We show that this solution can be obtained from theorems of the alternative and a useful characterization of solution sets of convex quadratic programs. By using an exterior penalty method, this problem can be reduced to an unconstrained minimization problem with once differentiable convex objective function. Also, we propose a quasi-Newton method for solving unconstrained optimization problem. Computational results show that convergence to high accuracy often occurs in just a few iterations.     

The Jacobian Conjecture,a Reduction of the Degree to the Quadratic Case

The Jacobian Conjecture states that any locally invertible polynomial system in \({{\mathbb{C}}^n}\) is globally invertible with polynomial inverse. Bass et al. (Bull Am Math Soc 7(2):287–330, 1982) proved a reduction theorem stating that the conjecture is true for any degree of the polynomial system if it is true in degree three. This degree reduction is obtained with the price of increasing the dimension \({n}\). We prove here a theorem concerning partial elimination of variables, which implies a reduction of the generic case to the quadratic one. The price to pay is the introduction of a supplementary parameter \({0 \leq n' \leq n}\), parameter which represents the dimension of a linear subspace where some particular conditions on the system must hold. We first give a purely algebraic proof of this reduction result and we then expose a distinct proof, in a Quantum Field Theoretical formulation, using the intermediate field method.     

The Gaussian Moments Conjecture and the Jacobian Conjecture

We first propose what we call the Gaussian Moments Conjecture. We then show that the Jacobian Conjecture follows from the Gaussian Moments Conjecture. Note that the the Gaussian Moments Conjecture is a special case of [11, Conjecture 3.2]. The latter conjecture was referred to as the Moment Vanishing Conjecture in [7, Conjecture A] and the Integral Conjecture in [6, Conjecture 3.1] (for the one-dimensional case). We also give a counter-example to show that [11, Conjecture 3.2] fails in general for polynomials in more than two variables.     

A Relaxed Case on 1-2-3 Conjecture

In 2004, Karoński, ?uczak and Thomason posed the conjecture that every graph admits a vertex-coloring edge 3-weighting using colors 1, 2, 3. In this paper, we prove that this conjecture is true if the vertex-coloring is relaxed to be a tree-coloring. Furthermore, we verify that some classes of graphs permit tree-coloring edge 2-weightings.     

The relation between the Baum-Connes Conjecture and the Trace Conjecture

We prove a version of the L ²-index Theorem of Atiyah, which uses the universal center-valued trace instead of the standard trace. We construct for G-equivariant K-homology an equivariant Chern character, which is an isomorphism and lives over the ring ℤ⊂λ ^G ⊂ℚ obtained from the integers by inverting the orders of all finite subgroups of G. We use these two results to show that the Baum-Connes Conjecture implies the modified Trace Conjecture, which says that the image of the standard trace K ₀(C ^* _r (G))→ℝ takes values in λ ^G . The original Trace Conjecture predicted that its image lies in the additive subgroup of ℝ generated by the inverses of all the orders of the finite subgroups of G, and has been disproved by Roy [15]. Oblatum 10-IV-2001 & 18-X-2001?Published online: 15 April 2002     

Completely Settling of the Multiplier Conjecture for the Case of n=3p~r

A k-subset D of a group G of order v (1 < k < v -1 ) is called a (v, k, )-difference set ifevery nonidentity element of G appears in the list of d1d2-1(d1, d2 D) exactly times. Setn = k - , n is called the order of difference set D.An taomorphism of a finite group G is called a (right) multiplier of a difference set D inG if sends D onto Da for some a G. If G is abelian and if is given by g gt, where t isan integer prime to the order of G, then and also t itself are called a numerical mul…     

Minimal Seifert manifolds and the knot finiteness theorem

It is proved that the Alexander modules determine the stable type of a knot up to finite ambiguity. The proof uses a new existence theorem of minimal Seifert surfaces for multidimensional knots of codimension two.     

A cut-and-paste method for computing the Seifert volumes

We use methods from gauge theory to compute the Seifert volumes of 3-manifolds. As applications, we are able to find the Seifert volumes of several hyperbolic manifolds obtained by surgery on 2-bridge knots.     

A volume-preserving counterexample to the Seifert conjecture

We prove that every 3-manifold possesses aC ¹, volume-preserving flow with no fixed points and no closed trajectories. The main construction is a volume-preserving version of the Schweitzer plug. We also prove that every 3-manifold possesses a volume-preserving,C ^∞ flow with discrete closed trajectories and no fixed points (as well as a PL flow with the same geometry), which is needed for the first result. The proof uses a Dehn-twisted Wilson-type plug which also preserves volume. The author was supported by an NSF Postdoctoral Fellowship, grant #DMS-9107908.     

On the Gronwall Conjecture

The Gronwall conjecture states that a planar 3-web which admits more than one distinct linearization is locally equivalent to an algebraic web. We give a partial answer to the conjecture in the affirmative for the class of planar 3-webs with web curvature that vanishes to order three at a point. The differential relation on the third-order jet of web curvature provides an explicit criterion for unique linearization.     

乘子猜想在n=5n_1时的一些结果

用［１］中的方法，我们得到乘子猜想在ｎ＝５ｎ１情形时的一些新结果，对此情形下的ＭａｃＦａｒｌａｎｄ的结论（见［２］）作了较大的改进．     

On the Bateman-Horn Conjecture

Let r be a positive integer and f₁,…,f_r be distinct polynomials in Z[X]. If f₁(n),…,f_r(n) are all prime for infinitely many n, then it is necessary that the polynomials f_i are irreducible in Z[X], have positive leading coefficients, and no prime p divides all values of the product f₁(n)···f_r(n), as n runs over Z. Assuming these necessary conditions, Bateman and Horn (Math. Comput.16 (1962), 363-367) proposed a conjectural asymptotic estimate on the number of positive integers n?x such that f₁(n),…,f_r(n) are all primes. In the present paper, we apply the Hardy-Littlewood circle method to study the Bateman-Horn conjecture when r?2. We consider the Bateman-Horn conjecture for the polynomials in any partition {f₁,…,f_s}, {f_s+1,…,f_r} with a linear change of variables. Our main result is as follows: If the Bateman-Horn conjecture on such a partition and change of variables holds true with some conjectural error terms, then the Bateman-Horn conjecture for f₁,…,f_r is equivalent to a plausible error term conjecture for the minor arcs in the circle method.     

Multiperiod Portfolio Optimization with Terminal Liability: Bounds for the Convex Case

This paper is concerned with an investor trading in multiple securities over many time periods in order to meet an outstanding liability at some future date. The investor is concerned with maximizing the expected profits from portfolio rebalancing under an initial wealth restriction to meet the future liabilities. We formulate the problem as a discrete-time stochastic optimization model and allow asset prices to have continuous probability distributions on compact domains. For the case of Markovian price uncertainty and convex terminal liability, we develop a simplicial approximation, under which bounds on the problem can be computed efficiently. Computations only require evaluating a dynamic programming recursion, which thus, allows its application to problems with a large number of trading periods. The bounds are tight in that they are exact in certain cases. Numerical results are given to demonstrate the computational efficiency of the procedure.     

Solution of the problem of describing minimal Seifert manifolds

We completely solve the Hayat-Legrand-Wang-Zieschang problem of listing all minimal Seifert manifolds (in the sense of degree 1 maps).     

Proof of the Jacobian Conjecture in the Two-Dimensional Case and Global Isochronous Centers of Polynomial Hamiltonian Differential Systems

Differential Equations - It is proved that, up to a nonsingular linear transformation, the real Hamiltonian system $$\dot {x}=-y-P(x) $$ , $$\dot {y}=x+(y+P(x))P^{\prime }(x) $$ , where $$P(x) $$...