共查询到20条相似文献,搜索用时 62 毫秒
1.
René L. Schilling 《Journal of Theoretical Probability》1998,11(2):303-330
Let {X
t}
t0 be a Feller process generated by a pseudo-differential operator whose symbol satisfiesÇn|q(Ç,)|c(1=)()) for some fixed continuous negative definite function (). The Hausdorff dimension of the set {X
t:tE}, E [0, 1] is any analytic set, is a.s. bounded above by dim E. is the Blumenthal–Getoor upper index of the Levy Process associated with (). 相似文献
2.
In this work we consider a system of partial differential operators D
1,D
2 on K=[0,+[×R, whose eigenfunctions are the functions (x,t), (x,t)K, =((R0)×N)(0×[0,+[), which are related to the Laguerre functions for ((R 0)×N)(0,0) and which are the Bessel functions for (0×[0,+[). We provide K and with a convolution structure. We prove a Lévy–Khintchine formula on K, which permits us to characterize dual convolution semigroups on . 相似文献
3.
For a graphG, letp(G) andc(G) denote the length of a longest path and cycle, respectively. Let (t,n) be the minimum ofp(G), whereG ranges over allt-tough connected graphs onn vertices. Similarly, let (t,n) be the minimum ofc(G), whereG ranges over allt-tough 2-connected graphs onn vertices. It is shown that for fixedt>0 there exist constantsA, B such that (t,n)A·log(n) and (t,n)·log((t,n))B·log(n). Examples are presented showing that fort1 there exist constantsA, B such that (t,n)A·log(n) and (t,n)B· log(n). It is conjectured that (t,n) B·log(n) for some constantB. This conjecture is shown to be valid within the class of 3-connected graphs and, as conjectured in Bondy [1] forl=3, within the class of 2-connectedK
1.l-free graphs, wherel is fixed. 相似文献
4.
Chang -Pao Chen 《Analysis Mathematica》1996,22(2):99-112
f(x,y)
jk
. , {c
jk} , f(x, )(, ) [0,1)х[0,1) , - (0,0). , , f, - f. , , , [1] . . - [5] [6].
This research is supported by National Science Council, Taipei, R.O.C. under Grant #NSC 84-2121-M-007-026. 相似文献
This research is supported by National Science Council, Taipei, R.O.C. under Grant #NSC 84-2121-M-007-026. 相似文献
5.
Domenico Perrone 《Monatshefte für Mathematik》1992,114(3-4):245-259
Contact Riemannian manifolds (M, ,g) satisfying the condition (1) =0, where is the torsion introduced byChern andHamilton [6] and is the characteristic vector field, have interesting geometric properties (see [6], [9], [11]). In this paper we give a variational characterization of compact contact Riemannian manifolds which satisfy (1). Moreover we study the tangent sphere bundles (T
1
M, , g), where (,g) is the standard contact Riemannian structure, which satisfy the condition (1); in particular in the 3-dimensional case we find a surprising result (see Corollary 5.3).Supported by funds of the M.U.R.S.T. 相似文献
6.
D. W. Schwendeman M. C. A. Kropinski J. D. Cole 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1993,44(3):556-571
Numerical calculations are carried out in the hodograph plane to construct optimal critical airfoil shapes and the flow about them. These optimal airfoil shapes give the highest free-stream Mach numberM
for a given thickness ratio and tail angle
t
(nonlifting) for which the flow is nowhere supersonic. A relationship betweenM
and for various
t
is given. Analytical and numerical solutions to the same problem are found on the basis of transonic small-disturbance theory. These results provide a limiting case asM
1, 0 and agree well with the calculations of the full problem. Using a numerical method to calculate the flow about general (subsonic) airfoils, a comparison is made between the critical free-stream Mach numbers for some standard airfoil shapes and the optimal free stream Mach number of the corresponding and
t
. A significant increase in the critical free-stream Mach number is found for the optimal airfoils. 相似文献
7.
Summary Throughout this paper the symbols r.v., d.f., ch.f., and i.d. will stand, respectively, for random variable, distribution function, characteristic function, and infinitely divisible.Let F(x) be an i.d.d.f. Hartman and Wintner [5] and Blum and Rosenblatt [1] have given a condition, necessary and sufficient, for F(x) to be a continuous d.f. In this note a sufficient condition for F(x) to be an absolutely continuous d.f. is given.Research supported by ONR Contract No. NONR-285(46).Research supported in part by a National Science Foundation fellowship. 相似文献
8.
P. D. Seymour 《Combinatorica》1996,16(2):223-231
LetG be an eulerian digraph; let (G) be the maximum number of pairwise edge-disjoint directed circuits ofG, and (G) the smallest size of a set of edges that meets all directed circuits ofG. Borobia, Nutov and Penn showed that (G) need not be equal to (G). We show that (G)=(G) provided thatG has a linkless embedding in 3-space, or equivalently, if no minor ofG can be converted toK
6 by –Y andY– operations. 相似文献
9.
M. Katchalski 《Aequationes Mathematicae》1978,17(1):249-254
Denoting by dimA the dimension of the affine hull of the setA, we prove that if {K
i:i T} and {K
i
j
:i T} are two finite families of convex sets inR
n
and if dim {K
i
:i S} = dim {K
i
j
:i S}for eachS T such that|S| n + 1 then dim {K
i
:i T} = dim {K
i
: {i T}}. 相似文献
10.
J. Balázs 《Acta Mathematica Hungarica》1998,80(3):237-248
In this paper we use (0, 2) interpolational polynomials to give an approximate solution of the differential equation y(x) + A(x)y(x) = F(x), x I := [-1, 1] j in case when the boundary values are y(-1) = and y(1) = , , R. 相似文献
11.
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
12.
Bang-Yen Chen 《Annals of Global Analysis and Geometry》1994,12(1):87-96
In the first part of this series, we prove that the tensor product immersionf
1
f
2k
of2k isometric spherical immersions of a Riemannian manifoldM in Euclidean space is of-type with k and classify tensor product immersionsf
1
f
2k
which are ofk-type. In this article we investigate the tensor product immersionsf
1
f
2k
which are of (k+1)-type. Several classification theorems are obtained. 相似文献
13.
T. F. Pankratova 《Journal of Mathematical Sciences》1986,32(2):196-204
The one-dimensional Schrödinger equation is considered on the segment [–l,l] It is assumed that the potential v(x) of this equation has one minimum v(0)=v(0)=0, v(0)>0 v(x)>0 for x0; v(x)h>0 outside some neighborhood of zero. It is proved that there exists a solution of the form where is a parabolic cylinder function, and is a smooth function which is bounded on [–l,l] together with derivatives through third order by a constant not depending on . The function and the real number E admit a known asymptotic expansion as 0.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 140, pp. 137–150, 1984. 相似文献
14.
Dr. Paul Ressel 《manuscripta mathematica》1975,16(1):47-49
A function : [0, )(-,0] is the logarithm of the Laplace transform of an infinitely divisible probability measure on [0,) if and only if (0)=0, is continuous and conditionally positiv semi-definite. 相似文献
15.
Mehdi Khayaty 《Southeast Asian Bulletin of Mathematics》2000,24(2):239-242
Let G be a transitive permutation group on a set and m a positive integer. If | – | m for every subset of and all g G, then || 2mp/(p – 1) where p is the least odd prime dividing |G|. It was shown by Mann and Praeger [13] that, for p = 3, the 3-groups G which attain this bound have exponent p. In this paper we will show a generalization of this result for any odd primes.AMS Subject Classification (2000), 20BXX 相似文献
16.
M. B. Nathanson 《Acta Mathematica Hungarica》2000,87(3):179-195
Let A be a set of positive integers with gcd (A) = 1, and let p
A
(n) be the partition function of A. Let c
0 = 2/3. If A has lower asymptotic density and upper asymptotic density , then lim inf log p
A
(n)/c
0 n and lim sup log p
A
(n)/c
0 n . In particular, if A has asymptotic density > 0, then log p
A
(n) c0n. Conversely, if > 0 and log p
A
(n) c
0 n, then the set A has asymptotic density . 相似文献
17.
Questions of approximative nature are considered for a space of functions L
p(G, ), 1 p , defined on a locally compact abelian Hausdorff group G with Haar measure . The approximating subspaces which are analogs of the space of exponential type entire functions are introduced. 相似文献
18.
R. Ž. Nurpeisov 《Analysis Mathematica》1989,15(2):127-143
H
(G), f(g)H
(G) , (, 1)- OHMC G. , OHMC, A. H. . , . , OHMC, lim supp
n=, , ,n .. . , 117 234 . . - 相似文献
19.
{p
mn
} -
00>0, (1, 1) (1.1) (1.2). {s
mn
} J
p
- ( bJ
p
-lims
mn
=), (1.3) 0<x,y<1 p
s
(, )/p(x, y) x, y 1-. {r
mn
} - , (1.5) 0<, <1. N
rp
- , (1.6). , bJ
p
-lims
mn
= bJ
q
-lim(N
rps)
mn
=. J
p
- . , . 相似文献
20.
In this article the topologically exact sequences
of locally convex spaces are characterized for which for every locally convex space F the map id : FE F Q is a homomorphism, or equivalently, the map id L : FK F E is a topological injection. This is motivated by the problem of lifting Q-valued functions with certain given properties to E-valued functions with the same or slightly weaker properties, which may also be considered as the investigation of parameter dependences of solutions of linear (differential) equations. Applications to partial differential equations and to Fredholm functions are given. 相似文献