共查询到20条相似文献,搜索用时 31 毫秒
1.
Gikō Ikegami 《Inventiones Mathematicae》1989,95(2):215-246
Summary We define a constraint system
, [0,0), which is a kind of family of vector fields
on a manifold. This is a generalized version of the family of the equations
, [0,0),x
m
,y
n
. Finally, we prove a singular perturbation theorem for the system
, [0,0).Dedicated to Professor Kenichi Shiraiwa on his 60th birthday 相似文献
2.
Pawel Hitczenko 《Probability Theory and Related Fields》1988,78(2):223-230
Summary It is shown that for all tangent sequences (d
n) and (e
n) of nonnegative or conditionally symmetric random variables and for every function satisfying the growth condition (2x)(x) the following inequality holds:
. This generalizes results of J. Zinn and proves a conjecture of S. Kwapie and W.A. Woyczyski. 相似文献
3.
Quadrature formulas obtained by variable transformation 总被引:1,自引:0,他引:1
Quadrature formulas suitable for evaluation of improper integrals such as
are obtained by means of variable transformations =tanhu and =erfu, and subsequent use of trapezoidal quadrature rule. Error analysis is carried out by the method of contour integral, and the results are confirmed on several concrete examples. Similar formulas are also obtained to accelerate the convergence of infinite integrals
by means of variable transformations =sinhu and =tanu. 相似文献
4.
Thomas Stehling 《Combinatorica》1992,12(4):475-479
We consider the numberN
A
(r) of subgroups of orderp
r
ofA, whereA is a finite Abelianp-group of type =1,2,...,
l
()), i.e. the direct sum of cyclic groups of order ii. Formulas for computingN
A
(r) are well known. Here we derive a recurrence relation forN
A
(r), which enables us to prove a conjecture of P. E. Dyubyuk about congruences betweenN
A
(r) and the Gaussian binomial coefficient
. 相似文献
5.
We consider strictly convex energy densities f: (x) under nonstandard growth conditions. More precisely, we assume that for some constants , and for all Z, Y
n
the inequality
holds with exponents and q< 1. If u denotes a bounded local minimizer of the energy f(w)dx subject to a constraint of the form w a.e. with a given obstacle C1, (), then we prove the local C
1,-regularity of u provided that q < 4 — . This result substantially improves what is known up to now even for the case of unconstrained local minimizers. Bibliography: 27 titles. 相似文献
6.
Summary We consider a (possibly) vector-valued function u: RN, Rn, minimizing the integral
, 2-2/(n*1)<p<2, whereD
i
u=u/x
i
or some more general functional retaining the same behaviour, we prove higher integrability for Du: D1 u,..., Dn–1 u Lp/(p-1) and Dnu L2; this result allows us to get existence of second weak derivatives: D(D1 u),...,D(Dn–1u)L2 and D(Dn u) L
p.This work has been supported by MURST and GNAFA-CNR. 相似文献
7.
Atube of even orderq=2
d
is a setT={L,
} ofq+3 pairwise skew lines in PG(3,q) such that every plane onL meets the lines of
in a hyperoval. Thequadric tube is obtained as follows. Take a hyperbolic quadricQ=Q
3
+
(q) in PG(3,q); letL be an exterior line, and let
consist of the polar line ofL together with a regulus onQ.In this paper we show the existence of tubes of even order other than the quadric one, and we prove that the subgroup of PL(4,q) fixing a tube {L,
} cannot act transitively on
. As pointed out by a construction due to Pasini, this implies new results for the existence of flat .C
2 geometries whoseC
2-residues are nonclassical generalized quadrangles different from nets. We also give the results of some computations on the existence and uniqueness of tubes in PG(3,q) for smallq. Further, we define tubes for oddq (replacing hyperoval by conic in the definition), and consider briefly a related extremal problem.Dedicated to luigi antonio rosati on the occasion of his 70th birthday 相似文献
8.
Joseph Rosenblatt 《Mathematische Annalen》1977,230(3):245-272
For a mean zero norm one sequence (f
n
)L
2[0, 1], the sequence (f
n
{nx+y}) is an orthonormal sequence inL
2([0, 1]2); so if
, then
converges for a.e. (x, y)[0, 1]2 and has a maximal function inL
2([0, 1]2). But for a mean zerofL
2[0, 1], it is harder to give necessary and sufficient conditions for theL
2-norm convergence or a.e. convergence of
. Ifc
n
0 and
, then this series will not converge inL
2-norm on a denseG
subset of the mean zero functions inL
2[0, 1]. Also, there are mean zerofL[0, 1] such that
never converges and there is a mean zero continuous functionf with
a.e. However, iff is mean zero and of bounded variation or in some Lip() with 1/2<1, and if |c
n
| = 0(n
–) for >1/2, then
converges a.e. and unconditionally inL
2[0, 1]. In addition, for any mean zerof of bounded variation, the series
has its maximal function in allL
p[0, 1] with 1p<. Finally, if (f
n
)L
[0, 1] is a uniformly bounded mean zero sequence, then
is a necessary and sufficient condition for
to converge for a.e.y and a.e. (x
n
)[0, 1]. Moreover, iffL
[0, 1] is mean zero and
, then for a.e. (x
n
)[0, 1],
converges for a.e.y and in allL
p
[0, 1] with 1p<. Some of these theorems can be generalized simply to other compact groups besides [0, 1] under addition modulo one. 相似文献
9.
We prove that, in a locally -solvable group G = AB with locally normal subgroups A and B, there exist pairwise-permutable Sylow - and p-subgroups A
, A
p
and B
, B
p
, p , of the subgroups A and B, respectively, such that A
B
is a Sylow -subgroup of the group G and, for an arbitrary nonempty set
,
are Sylow - and -subgroups, respectively, of the group G. 相似文献
10.
We investigate the problem of the boundedness of the following recurrence sequence in a Banach space B:
where |y
n} and |
n
} are sequences bounded in B, and A
k, k 1, are linear bounded operators. We prove that if, for any > 0, the condition
is satisfied, then the sequence |x
n} is bounded for arbitrary bounded sequences |y
n} and |
n
} if and only if the operator
has the continuous inverse for every z C, |z| 1. 相似文献
11.
Hauke Klein 《Geometriae Dedicata》1996,61(3):227-255
We consider a four-dimensional compact projective plane =(
,
) whose collineation group is six-dimensional and solvable with a nilradical N isomorphic to Nil × R, where Nil denotes the three-dimensional, simply connected, non-Abelian, nilpotent Lie group. We assume that fixes a flag pW, acts transitively on
p
\{W}, and fixes no point in the set W{p}. We study the actions of and N on
and on the pencil
p
\{W}, in the case that does not contain a three-dimensional elation group. In the special situation that acts doubly transitively on
p
{W}, we will determine all possible planes . There are exactly two series of such planes. 相似文献
12.
Let
for anyf H(R), where
(x): =
–1(x–1). Then (x) P
(x + h) for some h R and > 0; P denotes the Poisson kernel.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova Akademii Nauk SSSR, Vol. 170, pp. 82–89, 1989. 相似文献
13.
Bernard Petit 《Probability Theory and Related Fields》1992,93(4):407-438
Summary Let be an algebraic number greater than 1 andf a real 1-periodic function; ifF
N
denotes the random variable defined on [0, 1] byF
N
(t)
, it is proved here that under sufficiently broad assumptions onf: 1) the sequence
converges to a finite 2(0); 2) if >0, the sequence {F
N
} converges in law to
. We give an explicit computation of with respect to and a characterisation of functions for which =0.(Our results are also valid for almost every real >1). 相似文献
14.
In this paper we are concerned with the summability of the geometric series
by matrix methods. We prove the following theorem: Suppose Mo:={z:|z|<1}, M1, M2, is a collection of countably many Lebesgue measureable, disjoint sets. For k=1,2, let fk be a prescribed function, analytic on
. Then there exists a triangular matrix
, such that the V-transform {n(z)} of the geometric series has the following properties: {n(z)} converges compactly to
on Mo; for k=1,2, there are sets Bk, such that
has Lebesgue-measure zero and n(z)fk(z) for zBk; if
there is a set B*, such that B*M* has Lebesgue-measure zero and {n(z)} diverges for zB*. 相似文献
15.
G. V. Radzievskii 《Ukrainian Mathematical Journal》1994,46(5):581-603
We study the minimality of elementsx
h,j,k
of canonical systems of root vectors. These systems correspond to the characteristic numbers
k
of operator functionsL() analytic in an angle; we assume that operators act in a Hilbert space
. In particular, we consider the case whereL()=I+T()c, >0,I is an identity operator,C is a completely continuous operator, (I- C)–1c for ¦arg¦, 0<<, the operator functionT() is analytic, and T()c for ¦arg¦<. It is proved that, in this case, there exists >0 such that the system of vectorsC
v
x
h,j,k
is minimal in
for arbitrary positive <1+, provided that ¦k¦>.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 46, No. 5, pp. 545–566, May, 1994.This research was partially supported by the Ukrainian State Committee of Science and Technology. 相似文献
16.
Summary Least constantsc for the well-known Sobolev inequality fcf
m, G
,fH
m
(G) are obtained in closed form by a reproducing kernel technique, where the Sobolev spaceH
m
(G) for a domainG in
n
is defined as the completion ofC
m
(G) with respect to the Sobolev norm given by
, where is the norm ofL
2
(G) and is the supremum norm onG. Numerical values for the case whereG is the
n
are given. 相似文献
17.
In-Suk Wee 《Probability Theory and Related Fields》1990,85(4):469-488
Summary Let {X
t
} be a 1 process with stationary independent increments and its Lévy measurev be given byv{yy>x}=x
–L
1
(x), v{yy<–x}=x
–L
2
(x) whereL
1,L
2 are slowly varying at 0 and and 0<1. We construct two types of a nondecreasing functionh(t) depending on 0<<1 or =1 such that lim inf
a.s. ast 0 andt for some positive finite constantC.This research is partialy supported by a grant from Korea University 相似文献
18.
Aarni Lehtinen 《Mathematical Methods of Operations Research》1993,37(1):97-106
The secretary problem with a known prior distribution of the number of candidates is considered. Ifp(i)=p(N=i),i [, ] , where=inf{i :p(i) > 0} and=sup{i :p(i)0}, is the prior distribution of the numberN of candidates it will be shown that, if the optimal stopping rule is of the simple form, then the optimal stopping indexj=min satisfies asymptotically (as ) the equationj=exp
.The probability of selecting the best object by the corresponding policy will be (j-1)
p(i)/i. We also give an example of the distributionp for which the optimal stopping rule consists of a stopping set with two islands. We present an asymptotical solution for this example. 相似文献
19.
Klaus Menke 《Numerische Mathematik》1989,54(2):125-143
Summary LetD be the unit disk. It is a well-known fact that by use of simply connected domain methods the general conformal mapping problem of doubly connected domains can be reduced to the special case of a regionD bounded by the unit circle and a Jordan curve inD, where
. Here we treat this special case and assume to be piecewise analytic without cusps. Let be the conformal mapping of {<|w|<1} onto the doubly connected domainD with (1)=1. We approximate by interpolation with finite Laurent series using point systems with extremal properties. Numerical results for four examples are given. 相似文献
20.
Let M
f(r) and f(r) be, respectively, the maximum of the modulus and the maximum term of an entire function f and let be a continuously differentiable function convex on (–, +) and such that x = o((x)) as x +. We establish that, in order that the equality
be true for any entire function f, it is necessary and sufficient that ln (x) = o((x)) as x +. 相似文献