共查询到20条相似文献,搜索用时 15 毫秒
1.
William D. Banks 《Monatshefte für Mathematik》2012,75(1):157-163
Let φ be the Euler function. Fix , and let be an arbitrary set of primes of positive lower natural density. Using a variant of the Alford–Granville–Pomerance construction, we show that there are infinitely many Carmichael numbers N with a totient of the form , where and is a nonempty product of primes from the set . In particular, for any fixed natural number n, there are infinitely many Carmichael numbers N such that φ(N) = a 2 + nb 2 for some positive integers a and b. 相似文献
2.
3.
We prove that there does not exist a [q4+q3−q2−3q−1, 5, q4−2q2−2q+1]q code over the finite field
for q≥ 5. Using this, we prove that there does not exist a [gq(5, d), 5, d]q code with q4 −2q2 −2q +1 ≤ d ≤ q4 −2q2 −q for q≥ 5, where gq(k,d) denotes the Griesmer bound.MSC 2000: 94B65, 94B05, 51E20, 05B25 相似文献
4.
设U≥0表示一个固定单李代数的半量子群,给出了U≥0的性质和表示. 证明了Hopf代数U≥0不是拟余交换的,因此左U≥0模范畴不是辫子monoidal范畴. 在权模范畴W中,给出了所有单对象和投射对象. 最后描述了所有单的Yetter-Drinfel'd U≥0权模. 相似文献
5.
6.
本文研究亚纯函数的值分布问题.利用值分布理论,获得了一个带精简密指量的模分布的不等式,改进了Xu和Yang等人的结果. 相似文献
7.
8.
Antonio Cossidente 《Designs, Codes and Cryptography》2010,54(1):1-9
We will show that associated with the classical 1-system of the elliptic quadric Q
−(7, q) are certain infinite families of two-character sets with respect to hyperplanes, and partial ovoids of Q
+(15, q). 相似文献
9.
设m,n,L为正整数,本文证明了:如果mε,ε∈(0,1),且m>(123789LL(1/2))(1/(1-ε)),或j>10.25×1012log4(2(L+1)(123789LL(1/2))(1/(1-ε))),Pell方程组x2-(m2-1)y2=z2-(n2-1)y2=1的正整数解满足1≤k≤δL2,这里δ∈[1/2(123787LL(1/2))(1/(ε-1)),1],以及■且j=k=1或k+2≤j<1/3(5-2ε)k,2|(j+k),k>3/(1-ε),并改进了文[Proc.Amer.Math.Soc.,2015,143(11):4685-4693]的结果. 相似文献
10.
11.
Giuseppe Borrelli 《manuscripta mathematica》2009,130(4):523-531
We prove that if the bicanonical map of a minimal surface of general type S with p
g
= q = 1 and KS2=8{K_{S}^2=8} is nonbirational, then it is a double cover onto a rational surface. An application of this theorem is the complete classification
of minimal surfaces of general type with pg=q=1, KS2=8{p_{g}=q=1, K_{S}^2=8} and nonbirational bicanonical map. 相似文献
12.
In this paper, we study hypersurfaces of H2× H2. We first classify the hypersurfaces with constant principal curvatures and constant product angle functions. Then we classify homogeneous hypersurfaces and isoparametric hypersurfaces, respectively. Finally, we classify the hypersurfaces with at most two distinct constant principal curvatures, as well as those with three distinct constant principal curvatures under some additional conditions. 相似文献
13.
本文我们引入了函数类Bδ(G//K)={φ∈L1(G//K)||φ(t)|≤Δ-1(t)(1+t)1-δ,δ>0),对f∈Lp(G//K),1≤p≤∞,和极大算子(?),证明了这类算子是(H∞,s1,L1)型的. 相似文献
15.
16.
For any integersa
1,a
2,a
3,a
4 andc witha
1
a
2
a
3
a
4≢0(modp), this paper shows that there exists a solutionX=(x
1,x
2,x
3,x
4) ∈Z
4 of the congruencea
1
x
1
2
+a
2
x
2
2
+a
3
x
3
2
+a
4
x
4
2
≡c(modp) such that
Research of Zheng Zhiyong is supported by NNSF Grant of China. He would also like to thank the first author and the Mathematics
Department of Kansas, State University for their hospitality and support. 相似文献
17.
Romain Tessera 《Monatshefte für Mathematik》2011,61(4):115-118
The Schur algebra is the algebra of operators which are bounded on ℓ
1 and on ℓ
∞. In this note, we exhibit an element of the group algebra of the free group with two generators, which, as a convolution
operator, is invertible in ℓ
2, and whose inverse is not bounded on ℓ
1 nor on ℓ
∞. In particular, this shows that the Schur algebra is not inverse-closed. 相似文献
18.
Jimmy Petean 《Geometriae Dedicata》2009,143(1):37-48
We study isoperimetric regions on Riemannian manifolds of the form (M
n
× (0, π), sin2(t)g + dt
2) where g is a metric of positive Ricci curvature ≥ n − 1. When g is an Einstein metric we use this to compute the Yamabe constant of
(M ×\mathbbR, g+ dt2 ){(M \times \mathbb{R}, g+ dt^2 )} and so to obtain lower bounds for the Yamabe invariant of M × S
1. 相似文献
19.
设p 为奇素数且对任意的整数m, d, p≠(2m±1)=/d2, 则对任意的素数n > p8p2, 方程xn+2kyn=pz2, k≥2 没有整数解(x, y, z) 使得x, y, z 两两互素且均不为0. 相似文献
20.
Here we solve two problems presented in paper [9] (C C Tisdell and A Zaidi, Basic qualitative and quantitative results for
solutions to nonlinear, dynamic equations on time scales with an application to economic modelling, Nonlinear Anal.
68 (2008) 3504–3524). We study existence and uniqueness of solutions for delay systems and first-order dynamic equations of
the form x
Δ = f (t,x,x
σ
) on time scales by using the Banach’s fixed-point theorem. Some examples are presented to illustrate the efficiency of the
proposed results. 相似文献