共查询到20条相似文献,搜索用时 15 毫秒
1.
Takao Kato Changho Keem Akira Ohbuchi 《Abhandlungen aus dem Mathematischen Seminar der Universit?t Hamburg》1999,69(1):319-333
We give necessary and sufficient conditions for non-special line bundles of degree2g — 2 and 2g — 3 being not normally generated. We also provide criteria for special line bundles of degreed > 2g — 6 being normally generated.
This work was done under JSPS-KOSEF joint research program 1997. The first named author was partially supported by Grant-in-Aid
for Scientific Research, the Ministry of Education, #10440051. The second named author was partially supported by BSRI(1998-015-D00023)
and SNU(99-5-l-031). During the period when this paper was prepared for publication, the second named author was enjoying
the hospitality of ICTP. The third named author was partially supported by Grant-in-Aid for Scientific Research, the Ministry
of Education, #09640043. 相似文献
2.
A. Joós 《Acta Mathematica Hungarica》2008,119(4):307-321
We construct a convex body K ⊃ ℝ3 such that the maximum number of mutually nonoverlapping translates of K which touch K is 15.
The work is in part supported by grant no. T043556 of the Hungarian National Science Foundation (OTKA). 相似文献
3.
In this paper we introduce some modular forms of half-integral weight on congruence group Гo(4N) withN an odd positive integer which can be viewed as a natural generalization of Cohen-Eisenstein series. Using these series, we
can prove that the restriction of Shimura lifting on Eisenstein spaceE
k+1/2
+
(4N,χl) gives an isomorphism fromE
k+1/2
+
(4N,χl) toE
2k(N). We consider some congruence relationships between modular forms in use of Shimura lifting. 相似文献
4.
K. K. Muminov 《Russian Mathematics (Iz VUZ)》2009,53(6):24-28
We establish an equivalence criterion for finite systems of curves with respect to the action of the symplectic group. 相似文献
5.
Dan Ismailescu 《Periodica Mathematica Hungarica》2008,57(2):177-184
We prove that the interior of every convex polygon with n vertices (n ≥ 4) can be illuminated by four 45°-vertex lights. We restrict each vertex to anchoring at most one floodlight. This answers
a question of O’Rourke, Shermer and Streinu [5].
相似文献
7.
Vladimir Turaev 《Japanese Journal of Mathematics》2007,2(1):1-39
We discuss a topological approach to words introduced by the author in [Tu2]–[Tu4]. Words on an arbitrary alphabet are approximated
by Gauss words and then studied up to natural modifications inspired by the Reidemeister moves on knot diagrams. This leads
us to a notion of homotopy for words. We introduce several homotopy invariants of words and give a homotopy classification
of words of length five.
Based on notes by Eri Hatakenaka, Daniel Moskovich, and Tadayuki Watanabe 相似文献
8.
9.
We say that a convex set K in ? d strictly separates the set A from the set B if A ? int(K) and B ? cl K = ø. The well-known Theorem of Kirchberger states the following. If A and B are finite sets in ? d with the property that for every T ? A?B of cardinality at most d + 2, there is a half space strictly separating T ? A and T ? B, then there is a half space strictly separating A and B. In short, we say that the strict separation number of the family of half spaces in ? d is d + 2.In this note we investigate the problem of strict separation of two finite sets by the family of positive homothetic (resp., similar) copies of a closed, convex set. We prove Kirchberger-type theorems for the family of positive homothets of planar convex sets and for the family of homothets of certain polyhedral sets. Moreover, we provide examples that show that, for certain convex sets, the family of positive homothets (resp., the family of similar copies) has a large strict separation number, in some cases, infinity. Finally, we examine how our results translate to the setting of non-strict separation. 相似文献
10.
I. Kocsis 《Acta Mathematica Hungarica》2008,118(4):307-312
Let X ⊂ ℝ be an interval of positive length and define the set Δ = {(x, y) ∈ X × X | x ≧ y}. We give the solution of the equation
which holds for all (x, y) ∈ Δ and (u, υ) ∈ Δ, where the functions F: X → X, G
1: Δ → X, G
2: Δ → X, and G: F(X, X) × F(X, X) → X are continuous and strictly monotonic in each variable.
This research was supported by the Hungarian Scientific Research Fund (OTKA), grant No. T-043080. 相似文献
11.
Some remarks on trigonometric sums 总被引:1,自引:1,他引:0
Let
where m
1 < m
2 < … < m
t
≦ , δ
x
→ 0, p runs over the primes p ≧ ≦ 1, |X
p
| ≦ 1. It is assumed that m
v
, , X
p
may depend on x.
Assume that . It is proved that
for almost all irrational α, π(x) = number of primes up to x.
Research supported by the Applied Number Theory Research Group of the Hungarian Academy of Science and by a grant from OTKA
T46993. 相似文献
12.
E. N. Mikhalkin 《Russian Mathematics (Iz VUZ)》2009,53(6):15-23
In this paper we establish a relationship between two approaches to the solution of algebraic fifth-degree equations, namely, the Hermite-Kronecker method (based on the modular elliptic equation) and the Mellin method (based on hypergeometric series). 相似文献
13.
Tai-Chia Lin Chi-Cheung Poon Dong-Ho Tsai 《Calculus of Variations and Partial Differential Equations》2009,34(2):153-178
We study the evolution driven by curvature of a given convex immersed closed plane curve. We show that it will converge to
a self-similar solution eventually. This self-similar solution may or may not contain singularities. In case it does, we also
have estimate on the curvature blow-up rate. 相似文献
14.
Luis Fuentes García 《Archiv der Mathematik》2009,92(1):35-43
Let X be a smooth curve of genus g. When and d ≥ π−2g+1 we show the existence of a double covering where C a smooth curve of genus π with a base-point-free pencil of degree d which is not the pull-back of a pencil on X.
Received: 7 February 2007; Revised: 1 July 2008 相似文献
15.
This article investigates the convergence and growth of multiple Dirichlet series. The Valiron formula of Dirichlet series is extended to n-tuple Dirichlet series and an equivalence relation between the order of n-tuple Dirichlet series and its coefficients and exponents is obtained. 相似文献
16.
B. G. Grebenshchikov 《Russian Mathematics (Iz VUZ)》2009,53(2):30-40
In this paper we consider an ensemble of two subsystems of linear differential equations with constant delay. One of the subsystems contains an exponential multiplier in its right-hand side. We construct an asymptotically periodic solution of this system. 相似文献
17.
E. A. Utkina 《Russian Mathematics (Iz VUZ)》2009,53(4):40-44
We consider a problem with shifts in boundary conditions for the Bianchi equation in a four-dimensional space. We establish sufficient conditions which allow one to evaluate its unique solution in terms of the Riemann function. 相似文献
18.
Suppose that
is a 0-symmetric convex body
which denes the usual norm
on
. Let also
be a measurable set of positive upper density .
We show that if the body K is not a polytope, or if it is a polytope with
many faces (depending on ), then the distance set
contains all points t t0 for some positive number t0 . This was proved
by Furstenberg, Katznelson and Weiss, by Falconer and Marstrand and
by Bourgain in the case where K is the Euclidean ball in any dimension
greater than 1. As corollaries we obtain (a) an extension to any dimension
of a theorem of Iosevich and Laba regarding distance sets with respect to
convex bodies of well-distributed sets in the plane, and also (b) a new proof
of a theorem of Iosevich, Katz and Tao about the nonexistence of Fourier
spectra for smooth convex bodies with positive curvature. 相似文献
19.
We study the maximal term of the Hadamard composition of Dirichlet series with real exponents. We obtain a lower estimate for the sum of a Dirichlet series over a curve arbitrarily approaching the convergence line. 相似文献
20.
J. L. García-Roig Emma Martín-Gutiérrez 《Abhandlungen aus dem Mathematischen Seminar der Universit?t Hamburg》2000,70(1):85-92
We solve the functional equationf(x
3 +y
3) =f(x)3 +f(y)3 for maps of a finite field into itself. 相似文献