共查询到20条相似文献,搜索用时 31 毫秒
1.
Klaus Reuter 《Order》1989,6(3):277-293
It is known that for incidence structures
and
, max
, wheref dim stands for Ferrers relation. We shall show that under additional assumptions on
and
, both bounds can be improved. Especially it will be shown that the square of a three-dimensional ordered set is at least four-dimensional. 相似文献
2.
Given
, a compact abelian group G and a function
, we identify the maximal (i.e. optimal) domain of the convolution
operator
(as an operator from Lp(G) to itself). This is the
largest Banach function space (with order continuous norm) into which Lp(G)
is embedded and to which
has a continuous extension, still with values
in Lp(G). Of course, the optimal domain depends on p and g. Whereas
is compact, this is not always so for the extension of
to its optimal domain.
Several characterizations of precisely when this is the case are presented. 相似文献
3.
Milutin Dostanić 《Czechoslovak Mathematical Journal》1999,49(4):707-732
We find an exact asymptotic formula for the singular values of the integral operator of the form
, a Jordan measurable set) where
and L is slowly varying function with some additional properties. The formula is an explicit expression in terms of L and T. 相似文献
4.
5.
Harald Löwe 《Geometriae Dedicata》1995,58(1):45-51
We construct symmetric planes associated with an arbitrary locally compact connected nearfield
. If
is a proper nearfield, i.e.
{;;}, then the tangent translation plane of this symmetric plane is not classical. All previously known examples of symmetric planes have classical tangent translation planes.Herrn Professor Dr. H. Salzmann zum 65. Geburtstag gewidmet 相似文献
6.
We study the existence of classical (non-collision) T-periodic
solutions of the Hamiltonian system
where
and
is a T-periodic function in t which has a
singularity at
like
Under suitable conditions on H, we prove that if
then (HS) possesses at least one
non-collision solution and if
then the generalized solution of (HS) obtained in [5] has at most
one time of collision in its period. 相似文献
7.
Nicola Visciglia 《Calculus of Variations and Partial Differential Equations》2005,24(2):167-184
We present a generalized version of the Hardy-Sobolev inequality, in which the homogeneous potential
is replaced by any potential V belonging to the Lorentz space
. We show that the best constant in these inequalities is achieved provided that
where
. We also analyze the limit case
. Finally an application to a non-linear eigenvalues problem with rough potentials is presented.Received: 19 September 2004, Accepted: 15 November 2004, Published online: 22 December 2004 相似文献
8.
In this paper, we give an Lp-Lq-version of Morgans theorem for the Dunkl-Bessel transform
on
More precisely, we prove that for all
and
then for all measurable function f on
the conditions
and
imply f = 0, if and only if
where
are the Lebesgue spaces associated with the Dunkl-Bessel transform.Received: November 21, 2003 Revised: April 26, 2004 Accepted: May 28, 2004 相似文献
9.
For 1/p+1/q1, we study the closed ideal
formed by the (c
o
,p,q)-summing operators. It turns out thatT:XY does not belong to
if and only if it factors the mapId:l
p
*l
q
. By localization, we get the ideal
that consists of those operatorsT for which all ultrapowersT
u
are contained in
. Operators in the complement of
are characterized by the property that they factor the mapsId:l
p
*n
l
q
n
uniformly. Our main tools are ideal norms.Supported by DFG grant PI 322/1-2 相似文献
10.
Oversampling generates super-wavelets 总被引:1,自引:0,他引:1
Dorin Ervin Dutkay Palle Jorgensen 《Proceedings of the American Mathematical Society》2007,135(7):2219-2227
We show that the second oversampling theorem for affine systems generates super-wavelets. These are frames generated by an affine structure on the space .
11.
The solutions of the equation
in
, where
are investigated,
Bessel potentials of higher order are defined, and recurrence relations
between these solutions and these Bessel potentials are obtained. It is
also proved that these solutions and the solutions of
, under certain conditions, are identical.
Received: 6 November 2002 相似文献
12.
Antonio Corbo Esposito Riccardo De Arcangelis 《Annali di Matematica Pura ed Applicata》1993,164(1):155-193
A comparison between some relaxation methods of an integral functional is carried out. The following relaxed functionals of the variational integral I(, u)=
:
相似文献
13.
Considering mixed-norm sequence spaces lp,q, p, q 1, C. N. Kellogg proved the following theorem: if 1 < p 2 then
lp,2 and lp,2
, where 1/p + 1/p = 1. This result extends the Hausdorff-Young Theorem.We introduce here multiple mixed-norm sequence spaces
, examine their properties and characterize the multipliers of spaces of the form lp,[s;n],q, with the index s repeated n times. By an interpolation-type argument we prove that
(l,[2;n],2, lp,[1;n],1) for 1 < p 2. Using these results we obtain a further generalization of the Hausdorff-Young Theorem: if 1 < p 2 then
lp,[2;n] and lp,[2;n]
for each n = 0, 1, 2, ¨. The spaces lp,[2;n] decrease and lp,[2;n] increase properly with n for 1 < p < 2 and 1/p + 1/p = 1. We also extend a theorem of J. H. Hedlund on multiplers of Hardy spaces
and deduce other results. 相似文献
14.
Yoshitaka Uda 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1995,46(3):366-383
We study nonnegative solutions of the initial value problem for a weakly coupled system
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