共查询到20条相似文献,搜索用时 78 毫秒
1.
Karl Dilcher 《Aequationes Mathematicae》1994,48(1):55-85
Summary We study a class of generalized gamma functions
k
(z) which relate to the generalized Euler constants
k
(basically the Laurent coefficients of(s)) as (z) does to the Euler constant. A new series expansion for
k
is derived, and the constant term in the asymptotic expansion for log
k
(z) is studied in detail. These and related constants are numerically computed for 1 k 15. 相似文献
2.
Dr. H. Siebert 《Monatshefte für Mathematik》1976,82(4):327-336
The most well-known application of Montgomery's weighted sieve is to the so-called Brun-Titchmarsh inequality, which was proved byH. L. Montgomery andR. C. Vaughan in the form (x, k, l)2x((k)log(x/k))–1 for 1k<x, (k, l)=1, (x, k, l) being the number of primespx andpl modk, (k) being Euler's function. In this paper an upper estimate is given for a certain class of two-dimensional sieve problems, among them bounds for the number of twin primes and the number of Goldbach representations. 相似文献
3.
Colin de Vedière introduced an interesting linear algebraic invariant (G) of graphs. He proved that (G)2 if and only ifG is outerplanar, and (G)3 if and only ifG is planar. We prove that if the complement of a graphG onn nodes is outerplanar, then (G)n–4, and if it is planar, then (G)n–5. We give a full characterization of maximal planar graphs whose complementsG have (G)=n–5. In the opposite direction we show that ifG does not have twin nodes, then (G)n–3 implies that the complement ofG is outerplanar, and (G)n–4 implies that the complement ofG is planar.Our main tools are a geometric formulation of the invariant, and constructing representations of graphs by spheres, related to the classical result of Koebe about representing planar graphs by touching disks. In particular we show that such sphere representations characterize outerplanar and planar graphs. 相似文献
4.
Certain Convolution Operators for Meromorphic Functions 总被引:3,自引:0,他引:3
Dinggong Yang 《Southeast Asian Bulletin of Mathematics》2001,25(1):175-186
Let (p N) be the class of functions
analytic in 0 < |z| < 1. A convolution operator Lp(a, c) on p is introduced. This paper gives some sharp inequalities for f(z) satisfying Re{(1 – )zpLp(a, c) f(z) + zpLp(a + 1, c) f(z)} > , where 0, < 1, a > 0 and c 0, –1, –2,....AMS Subject Classification (1991) 30C45 30A10 相似文献
5.
Dr. Alexander Kovačec 《Monatshefte für Mathematik》1981,92(1):19-35
We shall develop a method to prove inequalities in a unified manner. The idea is as follows: It is quite often possible to find a continuous functional :
n
, such that the left- and the right-hand side of a given inequality can be written in the form (u)(v) for suitable points,v=v(u). If one now constructs a map
n
n
, which is functional increasing (i.e. for each x
n
(which is not a fixed point of ) the inequality (x)<((x)) should hold) one specially gets the chain (u)(
u))(
2(u))...
n
(u)). Under quite general conditions one finds that the sequence {
n
(u)}
n converges tov=v(u). As a consequence one obtains the inequality (u)(v). 相似文献
6.
We prove a local limit theorem (LLT) on Cramer-type large deviations for sums S
V
=
t
V (
t
), where
t
, t Z
, 1, is a Markov Gaussian random field, V Z
, and is a bounded Borel function. We get an estimate from below for the variance of S
V
and construct two classes of functions , for which the LLT of large deviations holds. 相似文献
7.
Summary It is proved that the operatorP: L
1 (0, ) L
1(0, ), given byPg(z) =
z/c
[g(x)/cx]dx, is completely mixing, i.e.,P
n
g
1 0 forg L
1(0, ) with g dx = 0. This implies that, forc (0, 1), each continuous and bounded solution of the equationf(x)=
0
cx
f(t)dt/(cx) (x (0, 1]) is constant. 相似文献
8.
Summary Statistical topography involves the study of the geometrical properties of the iso-sets (contour lines or surfaces) of a random potential (r). Previous work [1,2] has addressed coastlines on a random relief (x, y) that possess a single characteristic spatial scale with topography belonging to the universality class of the random percolation problem. In the present paper this previous analytical approach is extended to the case of a multiscale random function with a power spectrum of scales,
H
, in a wide range of wavelengths, 0 < <
m
. It is found that the pattern of the coastline differs significantly from that of a monoscale landscape provided that –3/4 <H < 1, with the case –3/4 <H < 0 corresponding to the long-range correlated percolation and 0 <H < 1 to the fractional Brownian relief. The expression for the fractal dimension of an individual coastline is derived,D
h
= (10 – 3H)/7, the maximum value of whichD
h = 7/4, corresponds to the monoscale relief. The distribution functionF(a) of level lines over their sizea is calculated:F(a) a
–4(1-H)/7, for 0 a
m
. A comparison of the theoretical results with geographical data is presented. 相似文献
9.
Per Grape 《BIT Numerical Mathematics》1991,31(3):394-405
The average case complexity classes P, L-samplable and NL, L-samplable are defined. We show that Deterministic Bounded Halting is complete for P, L-samplable and that Graph Reachability is complete for NL-samplable, both problems with a universal logspace samplable distribution. 相似文献
10.
Carl-Erik Fröberg 《BIT Numerical Mathematics》1966,6(3):191-211
We define the Möbius power series throughf(z)=
n-1
z
n
,g(z)=
n=1
(n)z
n
/n where (n) is the usual Möbius function. This paper presents some heuristic estimates describing the behavior off(z) andg(z) when |z| is close to 1 together with representations in terms of elementary functions for real values ofz. Function tables are also given together with zeros and a few other special values. 相似文献
11.
Summary We investigate generalizations of the classical Jensen and Chebyshev inequalities. On one hand, we restrict the class of functions and on the other we enlarge the class of measures which are allowed. As an example, consider the inequality (J)(f(x) d) A (f(x) d, d d = 1. Iff is an arbitrary nonnegativeL
x
function, this holds if 0, is convex andA = 1. Iff is monotone the measure need not be positive for (J) to hold for all convex withA = 1. If has higher monotonicity, e.g., is also convex, then we get a version of (J) withA < 1 and measures that need not be positive. 相似文献
12.
Wolfgang Grotz 《Monatshefte für Mathematik》1979,88(3):219-228
LetK be an algebraic number field, and for every integer K let () andd(), respectively, denote the number of relatively prime residue classes and the number of divisors of the principal ideal (). Asymptotic equalities are proved for the sums () and d
2(), where runs through certain finite sets of integers ofK. 相似文献
13.
Summary LetB=(B
t,t0) be a planar Brownian motion and let >0. For anyt0, the pointz=B
t is called a one-sided cone point with angle if there exist >0 and a wedgeW(,z) with vertexz and angle such thatB
sW(,z) for everys[t, t+]. Burdzy and Shimura have shown independently that one-sided cone points with angle exist when >/2 but not when 2. The present paper deals with the critical case =/2. We show that cone points with angle /2 do not exist. 相似文献
14.
E. P. Fadeeva 《Journal of Mathematical Sciences》1991,53(1):87-94
We present an explicit solution of the problem of optimal linear filtering: the recovery of the useful signal(s) at the instantt+, (>0,<0, or=0) from known values of the received signal(s)=(s)+(s) in the past, i.e., at the instantt–s, s0. In doing so we assume the random processes(s) and /gr(s) are stationary and jointly stationary, while the stationary process of noise (s) with zero mean is assumed to be mutually correlated and jointly stationary with the process(s) under the assumption that there exists a common spectral densityf() for these processes.Translated fromTeoriya Sluchaínykh Protsessov, Vol. 14, pp. 83–91, 1986. 相似文献
15.
N. A. Davydov 《Mathematical Notes》1972,11(4):263-265
For a preassigned unbounded sequence {Sn} of complex numbers, and preassigned complex numbers z1 and z2z1 we construct: 1) regular matrices A=ank and B=bnk such that the same bounded sequences are summable by these matrices and that
, and
; 2) regular matrices A(1))=a
nk
(1)
and B(1)=b
nk
(1)
such that B(1) A(1),
and,
. Our results show that the well known theorem of MazurOrlicz on the bounded consistency of two regular matrices, one of which is boundedly stronger than the other, is exact.Translated from Matematicheskie Zametki, Vol. 11, No. 4, pp. 431–436, April, 1972. 相似文献
16.
Bruno Kahn 《K-Theory》1991,5(6):555-566
Let F be a field, G
F its absolute Galois group, : G
FGL(C) a continuous complex representation of G
F and c
i() H2i(F, Z) its Chern classes. We show, under a mild assumption on F. that c
i ()=0 for all i2. For general F, one has that 2ci ()=0 for all i 2.
Cette dernière condition résulte en fait de la continuité de . 相似文献
17.
H. R. Hind 《Graphs and Combinatorics》1990,6(2):153-159
The total chromatic number,(G), of a graphG, is defined to be the minimum number of colours needed to colour the vertices and edges of a graph in such a way that no adjacent vertices, no adjacent edges and no incident vertex and edge are given the same colour. This paper shows that
, where(G) is the vertex chromatic number and(G) is the edge chromatic number of the graph.Partially supported by ORS grant ORS/84120 相似文献
18.
Xiuchun Li 《应用数学学报(英文版)》1987,3(4):374-383
In this paper we give a complete asymptotic expansion of the Jacobi functions
(, )
(t) as + . The method we employed to get the complete expansion follows that of Olver in treating similar problems. By using a Gronwall-Bellman type inequality for an improper integral in which the integrand is an unbounded function and contains a parameter, we get an error bound of the asymptotic approximation which is different from that of Olver's. 相似文献
19.
An overall bounded orthonormal set of functions
n
(x) is constructed for which there exists a series
m
=1 ann(x) with coefficients an=o(ln'n/n), which diverges to + almost everywhere. The bibliography contains 4 references.Translated from Matematicheskie Zametki, Vol. 2, No. 5, pp. 483–494, November, 1967. 相似文献
20.
F. Schipp 《Analysis Mathematica》1990,16(2):135-141
H={h
1,I } — , . : , I ¦(I)¦=¦I¦, ¦I¦ — I. H H
={h
(I),I} . , , . L
p
.
Dedicated to Professor B. Szökefalvi-Nagy on his 75th birthday
This research was supported in part by MTA-NSF Grants INT-8400708 and 8620153. 相似文献
Dedicated to Professor B. Szökefalvi-Nagy on his 75th birthday
This research was supported in part by MTA-NSF Grants INT-8400708 and 8620153. 相似文献