共查询到20条相似文献,搜索用时 109 毫秒
1.
I. F. Krasickov-Ternovskii 《Analysis Mathematica》1993,19(3):217-223
, . . - 1, ..., 4, — ; =(1,)×...×H(4), — H(1, ..., H(4), r H(1) — , 1 ; D: HH- . , D. , 1..., 4 , (.. z1 z+teia 1 t>0), W H . 相似文献
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4.
u=f(x)+S(u), S — , u-G(u), G —
. B
p,q
s
() -F
p,q
s
(). R
n
—
. — .
p,q
s
F
p,q
s
. 相似文献
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7.
Franz Kinzl 《Monatshefte für Mathematik》1979,87(2):109-121
LetS be a locally compact semigroup. It is shown that if a measure is absolutely continuous and ifS is cancellative, then the measure concentrated on a Borel subsetB ofS (i. e. =(B.)) is also absolutely continuous. Other properties of absolutely continuous measures will be obtained. Moreover we will answer the question when absolutely continuous probability measures exist. This is the case ifS admits an invariant integral on the space of all continuous functions onS with compact support. Another result is the following: If the compact semigroupS has a connected kernel then there exist absolutely continuous probability measures if and only ifS is amenable. 相似文献
8.
Bruno Gabutti 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1984,35(3):265-281
Summary Considerf+
ff+ (1–f2)+
f=0 together with the boundary conditionsf(0)=f(0)=0,f ()=1. If=–1,>0, arbitrary there is at least one solution which satisfies 0<f<1 on (0, ). By the additional conditionf>0 on (0, ) or, alternately 0<1, the uniqueness of the solution is demonstrated.If=1,<0, arbitrary the existence of solutions for which –1<f<0 in some initial interval (0,t) and satisfying generallyf>1 is established. In both problems, bounds forf (0) and qualitative behavior of the solutions are shown.
Sommario Si consideri il problema definito dall'equazionef+ f f+ (1–f2)+ f=0 e dalle condizioni al contornof(0)=f (0)=0,f()=1. Assumendo=–1,>0, arbitrario si dimostra che esiste almeno una soluzione che soddisfa 0<f<1 nell'intervallo (0, ). Se in aggiunta si ipotizzaf>0 in (0, ), oppure 0<=1, l'unicità délia soluzione è assicurata.Successivamente si considéra il problema di valori al contorno con=1,<0, arbitrario. In questo caso esiste un'intera classe di soluzioni che soddisfano –1<f<0 in un intorno dell'origine e tali chef>1, in generale.Di detti problemi viene studiato il comportamento délle soluzioni e vengono determinate dalle maggiorazioni e minorazioni del valoref(0).相似文献
9.
Johann Hartl 《Journal of Geometry》1988,31(1-2):89-95
If , , are linear mappings out of a projective space (P,G) into a projective space (P', G') and , then is said to belong to the pencil <,<> of linear mappings spanned by and if in the main (x), (x), (x) are collinear for all x P. We give some sufficient conditions for x P and , , such that (x) is uniquely determined by giving, and (z), z P.
Herrn Prof. Dr.Helmut Karzel zum 60. Geburtstag gewidmet 相似文献
Herrn Prof. Dr.Helmut Karzel zum 60. Geburtstag gewidmet 相似文献
10.
Let
n
be n-dimensional Euclidean space, and let : [0, L]
n
and : [0, L]
n
be closed rectifiable arcs in
n
of the same total length L which are parametrized via their arc length. is said to be a chord-stretched version of if for each 0s tL, |(t)–(s)| |(t)–(s)|. is said to be convex if is simple and if ([0, L]) is the frontier of some plane convex set. Individual work by Professors G. Choquet and G. T. Sallee demonstrated that if were simple then there existed a convex chord-stretched version of . This result led Professor Yang Lu to conjecture that if were convex and were a chord-stretched version of then and would be congruent, i.e. any chord-stretching map of a convex arc is an isometry. Professor Yang Lu has proved this conjecture in the case where and are C
2 curves. In this paper we prove the conjecture in general. 相似文献
11.
We give a combinatorial characterization of the Klein quadric in terms of its incidence structure of points and lines. As an application, we obtain a combinatorial proof of a result of Havlicek.In memoriam Giuseppe TalliniWork supported by National Research Project Strutture Geometriche, Combinatoria e loro applicazioni of the Italian Ministere dell'Università e della Ricerca Scientifica and by G.N.S.A.G.A. of C.N.R. 相似文献
12.
Timothy S. Norfolk 《Numerical Algorithms》2000,25(1-4):279-291
In this paper, we explore the asymptotic distribution of the zeros of the partial sums of the family of entire functions of order 1 and type 1, defined by G(,,z)=0
1(t)t
–1×(1–t)–1e
zt
dt, where Re,Re>0, is Riemann-integrable on [0,1], continuous at t=0, 1 and satisfies (0)(1)0. 相似文献
13.
Let (x) denote the number of those integers n with (n) x, where denotes the Euler function. Improving on a well-known estimate of Bateman (1972), we show that (x)-Ax R(x), where A=(2)(3)/(6) and R(x) is essentially of the size of the best available estimate for the remainder term in the prime number theorem. 相似文献
14.
Richard F. Kazmierczak Jr. 《Annals of Operations Research》2000,94(1-4):11-35
This paper presents an interdisciplinary approach to estimating the relative efficiency of static, myopic, and dynamic insecticide regulatory decision making when there are potential impacts associated with pest resistance. A theoretical control model was developed using expected total economic surplus as the objective function, with an empirical solution to the maximization problem attained by imposing a heuristic search procedure on a bioeconomic simulation model. Although the impact of nondynamic decision making was the most severe, in percentage terms, for shortrun planning horizons, the magnitude of the longrun losses associated with nondynamic decision making could serve as a rationale for modifying the regulatory process to include dynamic considerations. The static analyses usually used in the benefits assessment procedure may severely underestimate the actual benefits of continued chemical registration, and the efficiency gains to society have the potential to offset the increased costs of regulation that would occur under a revised process. 相似文献
15.
Existence for the Cahn-Hilliard phase separation model with a nondifferentiable energy 总被引:3,自引:0,他引:3
Summary The Cahn-Hilliard model for phase separation in a binary alloy leads to the equations (I) ut=w, (II) w= (u)– u with an associated energy functional F(u)=f [(u)+ +¦u¦2/2] dx. In this paper we discuss the existence theory for initial bounday value problems arising from modifications to the Cahn-Hilliard model due to the addition of the non-differentiable term ¦u¦dx to the energy F(u). 相似文献
16.
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
17.
Harry Dym 《Integral Equations and Operator Theory》1978,1(2):152-175
In this paper we shall study the Fredholm determinant and related trace formulas for a class of operators which correspond to the restriction of integral operators with kernels of the form k(x,y) = (x)gv(x–y)+[1–(x)]fv(x–y) to the square |x|,|y| T and shall evaluate the limit as T . Here denotes the indicator function of the right half-line [0,) . The results obtained generalize the well known formulas of M. Kac for the classical convolution operator in which g = f . 相似文献
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19.
Horst Elmar Winkelnkemper 《Annals of Global Analysis and Geometry》1992,10(3):209-218
Let
t
be the flow (parametrized with respect to arc length) of a smooth unit vector field v on a closed Riemannian manifold M
n
, whose orbits are geodesics. Then the (n-1)-plane field normal to v, v, is invariant under d
t
and, for each x M, we define a smooth real function
x
(t) : (1 +
i
(t)), where the i(t) are the eigenvalues of AA
T, A being the matrix (with respect to orthonormal bases) of the non-singular linear map d2t
, restricted to v at the point x
-t M
n.Among other things, we prove the
Theorem (Theorem II, below). Assume v is also volume preserving and that
x
'
(t) 0 for all x M and real t; then, if
x
t
: M M is weakly missng for some t, it is necessary that vx 0 at all x M. 相似文献
20.
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