Sums of nine almost equal prime cubes

We prove that each sufficiently large odd integer N can be written as sum of the form N = p1^3 ＋p2^3 ＋... ＋p9^3 with [pj - （N/9）^1/31 ≤ N^（1/3）-θ, where pj, j = 1,2,...,9, are primes and θ = （1/51） -ε.     

Hua＇s Theorem on Five Almost Equal Prime Squares

In this paper we sharpen Hua＇s result by proving that each sufficiently large integer N congruent to 5 modulo 24 can be written as N=p1^2＋p2^2＋p3^2＋p4^2＋p5^2,with │pj-√N/5│≤U=N^1/2-1/28＋ε,where pj are primes.     

On the diophantine equation x 2 − Dy 2 = n

We propose a method to determine the solvability of the diophantine equation x2-Dy2=n for the following two cases:(1) D = pq,where p,q ≡ 1 mod 4 are distinct primes with(q/p)=1 and(p/q)4(q/p)4=-1.(2) D=2p1p2 ··· pm,where pi ≡ 1 mod 8,1≤i≤m are distinct primes and D=r2+s2 with r,s ≡±3 mod 8.     

多元三角代换解题例说

三角代换是求解代数问题的一种重要转化方法 ,特别在涉及条件最值 (值域 )、条件不等式的证明时 ,巧用三角代换 ,常常可达到化繁为简、化难为易之功效 .这里用一组实例来说明多变元三角代换的应用 .例 1　设 p >0、q >0 ,且 p3 q3=2 .求证 :p q≤ 2 .证明　令 p q =s,因 p >0 ,q >0 ,故可设 p =s. cos2 θ、q =s. sin2 θ,代入 p3 q3= 2得s3=2cos6θ sin6θ= 2( cos2 θ sin2 θ) ( cos4 θ- cos2 θsin2 θ sin4 θ)= 2( cos2θ sin2θ) 2 - 3cos2θsin2θ= 21 - 34sin2 2θ≤ 21 - 34=8.∴　 s≤ 2 ,即　 p q≤ 2 .评注　本…     

HUA’S THEOREM WITH FIVE ALMOST EQUAL PRIME VARIABLES

It is proved that each sufficiently large integer N=5(mod24) can be written as N=p1^2+p2^2+p3^2+p4^2+p5^2 with|pj=√N/5|±、≤U=N^1/2-1/35+e,where pj ae primes.This result,which is obtained by an iterative method and a hybrid estimate for Dirichlet polynomial, improves the previous results in this direction.     

关于一个素数和一个素数的k次方和问题

设k≥2,Hk表示一个正整数n的集合,使对任意的正整数q,同余方程a+b2三n(modq)在模q的既约剩余系中有解a,b.Dk(N)表示n≤N,n∈Hk,但不能表成p1+p22=n的数的个数,其中p1,p2表示素数.则在GRH下,Dk(N)<<N1-1/k(h(k)+1)+ε,这里k=2,3;h(2)=2,h(3)=8.     

关于f（n）模1的分布

1 引言 设a是一个实数,k是一个自然数。我们用[θ]表示实数θ到最近整数的距离。对k=1我们有狄立克莱定理。对任何N≤1均存在自然数n≤N使 |an|≤N~(-1)(1)对k=2,Heilbronn证明了:假如给定ε>0和N≥N(ε),那么存在自然数n≤N使得     

关于一个素数和一个素数的k次方和问题

设k≥2,且Hk表示一个正整数n的集合,使得该集合中的元素满足a+bk≡n(modq)对任意的q,在模q的既约剩余系中有解,令Dk(N)表示所有的n≤N,且n∈Hk且不能表成p1+p2k=n形式的整数.那么在GRH下, Dk(N)相似文献   

Sums of Five Almost Equal Prime Squares

Let Pi, 1≤i≤5, be prime numbers. It is proved that every integer N that satisfies N=5 （mod 24） can be written as N=p1^2＋p2^2＋P3^2＋p4^2 ＋p5^2, where │√N5-Pi│≤N^1/2-19/850＋∈.     

九个几乎相等的素数的立方之和

本文证明了每个充分大的奇数N.可以表为九个几乎相等的素数的立方之和, 即N=p13+…+p39,这里|Pj-3((N/9)~(1/2))|≤U=N1/3-2/555+ε,从而进一步深化了华罗庚教授的经典结果．我们利用Dirichlet多项式的混合型估计及一个新的迭代方法建立了这一结果．     

Adams谱序列上的非平凡乘积b_0k_0δ_(s+4)

主要用May谱序列证明了非平凡的乘积b_0k_0δ_(s+4)∈Ext_A~(s+8,t)(Z_p,Z_p),其中p是大于等于7的素数,0≤sp-4,q=2(p-1),t=(s+4)p~3q+(s+3)p~2q+(s+5)pq+(s+2)q+s.     

Torsion points on the jacobian of a Fermat quotient

Let p≥5 be a prime, ζ a primitive pth root of unity and λ=1−ζ. For 1≤s≤p−2, the smooth projective model C_p,s of the affine curve v^p=u^s(1−u) is a curve of genus (p−1)/2 whose jacobian J_p,s has complex multiplication by the ring of integers of the cyclotomic field Q(ζ). In 1981, Greenberg determined the field of rationality of the p-torsion subgroup of J_p,s and moreover he proved that the λ³-torsion points of J_p,s are all rational over Q(ζ). In this paper we determine quite explicitly the λ³-torsion points of J_p,1 for p=5 and p=7, as well as some further p-torsion points which have interesting arithmetical applications, notably to the complementary laws of Kummer’s reciprocity for pth powers.     

Difference Sets Corresponding to a Class of Symmetric Designs

We study difference sets with parameters(v, k, ) = (p ^s(r ^2m - 1)/(r - 1), p ^s-1 r ^2m-2 r - 1)r ^{2m -2}, where r = r ^s - 1)/(p - 1) and p is a prime. Examples for such difference sets are known from a construction of McFarland which works for m = 1 and all p,s. We will prove a structural theorem on difference sets with the above parameters; it will include the result, that under the self-conjugacy assumption McFarland's construction yields all difference sets in the underlying groups. We also show that no abelian .160; 54; 18/-difference set exists. Finally, we give a new nonexistence prove of (189, 48, 12)-difference sets in Z ₃ × Z ₉ × Z ₇.     

A Szemerédi-type regularity lemma in abelian groups, with applications

Szemerédi’s regularity lemma is an important tool in graph theory which has applications throughout combinatorics. In this paper we prove an analogue of Szemerédi’s regularity lemma in the context of abelian groups and use it to derive some results in additive number theory. One is a structure theorem for sets which are almost sum-free. If has δ N² triples (a₁, a₂, a₃) for which a₁ + a₂ = a₃ then A = B ∪ C, where B is sum-free and |C| = δ′N, and as Another answers a question of Bergelson, Host and Kra. If 0,$$" align="middle" border="0"> if \,N_{0}(\alpha, \epsilon)$$" align="middle" border="0"> and if has size α N, then there is some d ≠ 0 such that A contains at least three-term arithmetic progressions with common difference d.Received: November 2003 Revision: October 2004 Accepted: December 2004     

Maximal Inequalities and Lebesgue's Differentiation Theorem for Best Approximant by Constant over Balls

For fL_p( ⁿ), with 1p<∞, >0 and x ⁿ we denote by T(f)(x) the set of every best constant approximant to f in the ball B(x, ). In this paper we extend the operators T_p to the space L_p−1( ⁿ)+L_∞( ⁿ), where L₀ is the set of every measurable functions finite almost everywhere. Moreover we consider the maximal operators associated to the operators T_p and we prove maximal inequalities for them. As a consequence of these inequalities we obtain a generalization of Lebesgue's Differentiation Theorem.     

Interpolation of Banach Lattices and Factorization of p-Convex and q-Concave Operators

We extend a result of ?estakov to compare the complex interpolation method [X ₀, X ₁]_θ with Calderón-Lozanovskii’s construction ${{{{X^{1-\theta}_{0}X^{\theta}_{1}}}}}We extend a result of Šestakov to compare the complex interpolation method [X ₀, X ₁]_θ with Calderón-Lozanovskii’s construction X^1-q₀X^q₁{{{{X^{1-\theta}_{0}X^{\theta}_{1}}}}}, in the context of abstract Banach lattices. This allows us to prove that an operator between Banach lattices T : E → F which is p-convex and q-concave, factors, for any q ? (0, 1){{{{\theta \in (0, 1)}}}}, as T =  T ₂ T ₁, where T ₂ is ( (\fracpq+ (1 - q)p ){{\left({\frac{p}{{\theta + (1 - \theta)p}}} \right)}}-convex and T ₁ is (\fracq1 - q ){{\left({\frac{q}{{1 - \theta }}} \right)}}-concave.     

Distribution of harmonic sums and Bernoulli polynomials modulo a prime

For a fixed integer s≥1, we estimate exponential sums with harmonic sums individually and on average, where H_s(n) is computed modulo a prime p. These bounds are used to derive new results about various congruences modulo p involving H_s(n). For example, our estimates imply that for any ɛ>0, the set {H_s(n):n<p^1/2+ɛ} is uniformly distributed modulo a sufficiently large p. We also show that every residue class λ can be represented as with max{n_ν|ν=1,. . . , 7}≤p^11/12+ɛ, and we obtain an asymptotic formula for the number of such representations. The same results hold also for the values B_p−r(n) of Bernoulli polynomials where r is fixed, complementing some results of W. L. Fouche. During the preparation of this paper, F. L. was supported in part by grants SEP-CONACYT 37259-E and 37260-E, and I. S. was supported in part by ARC grant DP0211459.     

Nonradial Large Solutions of Sublinear Elliptic Equations

We show that the equation Δu = p(x)f(u) has a positive solution on R ^N , N ≥ 3, satisfying <artwork name="GAPA31011ei1"> <artwork name="GAPA31011ei2"> if and only if <artwork name="GAPA31011ei3"> when ψ(r) = min{p(x): |x| = r}. The nondecreasing continuous function f satisfies f(0) = 0, f (s) > 0 for s > 0, and sup _{s ≥ 1} f(s)/s<∞, and the nonnegative continuous function p is required to be asymptotically radial. This extends previous results which required the function p to be constant or radial.     

Continuity envelopes of spaces of generalised smoothness, entropy and approximation numbers

We study continuity envelopes in spaces of generalised smoothness B_pq^(s,Ψ) and F_pq^(s,Ψ) and give some new characterisations for spaces B_pq^(s,Ψ). The results are applied to obtain sharp asymptotic estimates for approximation numbers of compact embeddings of type id:B_pq^(s₁,Ψ)(U)→B_∞∞^s₂(U), where and U stands for the unit ball in . In case of entropy numbers we can prove two-sided estimates.     

Sums of almost equal prime cubes

We prove that almost all integers N satisfying some necessary congruence conditions are the sum of j almost equal prime cubes with j = 5; 6; 7; 8, i.e., N = p ₁³ + ... + p _j ³ with |p _i − (N/j)^1/3| ≦ $ N^{1/3 - \delta _j + \varepsilon } $ N^{1/3 - \delta _j + \varepsilon } (1 ≦ i ≦ j), for δ _j = 1/45; 1/30; 1/25; 2/45, respectively.