共查询到20条相似文献,搜索用时 437 毫秒
1.
2.
Yuanji Cheng 《Czechoslovak Mathematical Journal》1997,47(4):681-687
In this paper, we consider the existence and nonexistence of positive solutions of degenerate elliptic systems
where –p is the p-Laplace operator, p > 1 and is a C
1,-domain in
. We prove an analogue of [7, 16] for the eigenvalue problem with
and obtain a non-existence result of positive solutions for the general systems. 相似文献
3.
Rejeb HADIJI 《数学年刊B辑(英文版)》2007,28(3):327-352
The authors consider the problem: -div(p▽u) = uq-1 λu, u > 0 inΩ, u = 0 on (?)Ω, whereΩis a bounded domain in Rn, n≥3, p :Ω→R is a given positive weight such that p∈H1 (Ω)∩C(Ω),λis a real constant and q = 2n/n-2, and study the effect of the behavior of p near its minima and the impact of the geometry of domain on the existence of solutions for the above problem. 相似文献
4.
E. S. Dubtsov 《Journal of Mathematical Sciences》2005,129(4):3990-3993
Let Hp be the Hardy space in the polydisk. Denote by
the set of all holomorphic polynomials. A vector f ∈ Hp is called weakly cyclic if the product f
is weakly dense in Hp, 0 < p < 1. We construct weakly cyclic vectors with a prescribed lower semi-continuous modulus of the boundary values. Bibliography: 6 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 303, 2003, pp. 111–118. 相似文献
5.
V. M. Badkov 《Mathematical Notes》1973,13(5):453-459
For the polynomials {pn(t)}
0
, orthonormalized on [–1, 1] with weightp(t) = (1–t) (1+t)
v=1
m
, we obtain necessary and sufficient conditions for boundedness of the sequences of norms: 1)
2)
and 3)
with the conditions that
on [–1, 1] and (H,)–1 L2(0, 2), where(H,) is the modulus of continuity in C(–1, 1) of function H.Translated from Matematicheskie Zametki, Vol. 13, No. 5, pp. 759–770, May, 1973. 相似文献
6.
B. Yousefi 《Czechoslovak Mathematical Journal》2004,54(1):261-266
Let
be a sequence of positive numbers and 1 p< . We consider the space H
p() of all power series
such that
. We investigate strict cyclicity of
the weakly closed algebra generated by the operator of multiplication by zacting on H
p(), and determine the maximal ideal space, the dual space and the reflexivity of the algebra
. We also give a necessary condition for a composition operator to be bounded on H
p() when
is strictly cyclic. 相似文献
7.
8.
Majorants and Extreme Points of Unit Balls in Bernstein Spaces 总被引:1,自引:1,他引:0
The Bernstein space B
p () (1
$$
" align="middle" border="0">
0) is the set of functions from L
p(
) having Fourier transforms (in the sense of generalized functions) with supports in the compact segment [- , ]. Every function f
has an analytic continuation onto the complex plane, which is an entire function of exponential type . The spaces B
p ()\, are conjugate Banach spaces. Therefore, the closed unit ball
in B
p () has a rich set of extreme (boundary) points:
coincides with the weakly * closed convex hull of its extreme points. Since, for 1< p< , B
p () is a uniformly convex space, only the balls
and
have nontrivially arranged sets of extreme points. In this paper, in terms of zeros of entire functions, we obtain necessary and sufficient conditions of extremeness for functions from
. 相似文献
9.
Consider the minimization problem
in which
is a normal integrand. Define the convex function
by
It is known that, if the essential domain H of G is open, then problem (P) has a minimizer for any pair of endpoints (u
0, u
1). In this paper, the same result is proved under the condition that, for every point p in H, the subgradient set G(p) is either bounded or empty (when H is open, this condition holds automatically). 相似文献
10.
Marco Buratti 《Designs, Codes and Cryptography》2002,26(1-3):111-125
We prove the existence of a cyclic (4p, 4, 1)-BIBD—and hence, equivalently, that of a cyclic (4, 1)-GDD of type 4
p
—for any prime
such that (p–1)/6 has a prime factor q not greater than 19. This was known only for q=2, i.e., for
. In this case an explicit construction was given for
. Here, such an explicit construction is also realized for
.We also give a strong indication about the existence of a cyclic (4p 4, 1)-BIBD for any prime
, p>7. The existence is guaranteed for p>(2q
3–3q
2+1)2+3q
2 where q is the least prime factor of (p–1)/6.Finally, we prove, giving explicit constructions, the existence of a cyclic (4, 1)-GDD of type 6
p
for any prime p>5 and the existence of a cyclic (4, 1)-GDD of type 8
p
for any prime
. The result on GDD's with group size 6 was already known but our proof is new and very easy.All the above results may be translated in terms of optimal optical orthogonal codes of weight four with =1. 相似文献
11.
N. A. Shirokov 《Journal of Mathematical Sciences》2005,129(4):4083-4086
Let
n be the unit ball in ℂn, n ≥ 2. Let Tα = {z ∈
n : (z, a) = |a|2} for a ∈
n and denote
for a discrete set A in
n. We find a sharp necessary condition for a set A to be a part of the zero-set for a function in H∞(
n). Bibliography 4 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 303, 2003, pp. 272–278. 相似文献
12.
M. A. Herrero M. Ughi J. J. L. Velázquez 《NoDEA : Nonlinear Differential Equations and Applications》2004,11(1):1-28
We consider here the homogeneous Dirichlet problem for the equation
, in a noncylindrical domain in space-time given by
. By means of matched asymptotic expansion techniques
we describe the asymptotics of the maximal solution approaching the vertex
x=0,
t=T, in the three different
cases p>1/2, p=1/2(vertex regular),
p<1/2 (vertex irregular). 相似文献
13.
Atsushi Uchiyama 《Integral Equations and Operator Theory》1999,33(2):221-230
For an-multicyclicp-hyponormal operatorT, we shall show that |T|2p
–|T
*|2p
belongs to the Schatten
and that tr
Area ((T)). 相似文献
14.
15.
Benjamin A. Lotto 《Integral Equations and Operator Theory》1990,13(2):216-230
For a given functionb in the unit ball ofH
and an arbitraryH
functionm, the question of whenm is a multiplier of the de Branges space
(that is, when
is invariant under multiplication bym) is examined. Some necessary and sufficient conditions thatm be a multiplier of
are found and it is shown that there are no nonconstant inner multipliers of
whenb is a nonconstant extreme point of the unit ball ofH
. A new proof is given of the known fact that
is invariant under multiplication byz whenb is not an extreme point of the unit ball ofH
. Finally, we give a new proof of the known fact that an inner functionm is a multiplier of
forb(z)=(1+z)/2 if and only ifm belongs to the range of
.Some of the work in this paper originally appeared in the author's doctoral disseratation written at the University of California at Berkeley under the supervision of Donald Sarason. 相似文献
16.
This paper, self-contained, deals with pseudo-unitary spin geometry. First, we present pseudo-unitary conformal structures
over a 2n-dimensional complex manifold V and the corresponding projective quadrics
for standard pseudo-hermitian spaces Hp,q. Then we develop a geometrical presentation of a compactification for pseudo-hermitian standard spaces in order to construct
the pseudo-unitary conformal group of Hp,q. We study the topology of the projective quadrics
and the “generators” of such projective quadrics. Then we define the space S of spinors canonically associated with the pseudo-hermitian scalar product of signature (2n−1, 2n−1). The spinorial group Spin U(p,q) is imbedded into SU(2n−1, 2n−1). At last, we study the natural imbeddings of the projective quadrics
相似文献
17.
Niels Jakob Laustsen 《K-Theory》2001,23(2):115-127
We prove that the K-groups of the Banach algebra
of bounded, linear operators on the pth James space
, where 1 < p < , are given by
and
. Moreover, for each Banach space
and each non-zero, closed ideal
contained in the ideal of inessential operators, we show that
and
. This enables us to calculate the K-groups of
for each Banach space
which is a direct sum of finitely many James spaces and
-spaces. 相似文献
18.
We study Banach spaces of the form
We call such a space a p-space, p[1,), if for every k the space
is isomorphic to pk and the sequence (pk) strictly decreases to p. We examine the finite block representability of the spaces r in a p-space proving that it depends not only on p but also on the sequences (pk) and (nk). Assuming that i ni
1/q decreases to 0, where q is the conjugate exponent of p, we prove the existence of an asymptotic biorthogonal system in X and also that c
0 is finitely representable in X. Moreover we investigate the modified versions of p-spaces proving that, if nkm1/pkm-1/pkm-1 increases to infinity for a subsequence (nkm) , then 1 embeds into X. We also investigate complemented minimality for the class of spaces
where
is either a subsequence of the sequence of Schreier classes (
n)n N or a subsequence of (
n)n N. 相似文献
19.
It is proved that the initial-value problem for
admits a unique continuous viscosity solution under certain conditions
which do not exclude that H(x, p) is discontinuous in
x. Particular
attention is devoted to the linear transport equation
, where a may be discontinuous.
Received: 21 October 2002 相似文献
20.
Let p be a prime,
a finite p-group,
any finite group with order divisible by p,
and
any action of
on
. We show that the cardinality of the set of all derivations
with respect to this action is a multiple of
p. This
generalises theorems of Frobenius and Hall.
Received: 16 June 2003 相似文献