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1.
Milutin Dostanić 《Journal d'Analyse Mathématique》2008,104(1):13-23
It is shown that the Berezin transform B on L
p
(D), where D is the unit disc, has norm
. Furthermore, the norms of a family of operators (on L
p
(D)) whose kernels are moduli of Bergman type kernels are also calculated.
Partially supported by MNZZS, Grant
ON144010 相似文献
2.
For a big number of varieties
of groups close to Engelian, it is proved that a variety of lattice-ordered groups generated by all linearly ordered groups
in the class
does not coincide with the variety
of all o-approximable lattice-ordered groups.
Supported by FP “Universities of Russia” grant No. UR.04.01.001.
__________
Translated from Algebra i Logika, Vol. 45, No. 1, pp. 20–27, January–February, 2006. 相似文献
3.
4.
We study various Sp(2M)-invariant field equations corresponding to rank-r tensor products of the Fock (singleton) representation
of Sp(2M). These equations describe localization on “branes” of different dimensions embedded in the generalized space-time
with matrix (i.e., “central charge”) coordinates. We consider the case of a bilinear tensor product in detail and show that
the conserved currents built from bilinears of rank-1 fields in
satisfy the field equations for rank-2 fields in
. We also show that rank-2 fields in
are equivalent to rank-1 fields in
.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 145, No. 1, pp. 35–65, October, 2005. 相似文献
5.
I. Kátai 《Lithuanian Mathematical Journal》2007,47(1):24-31
We characterize the q-multiplicative functions which belong to
or
= the set of uniformly summable functions on the set of primes.
Dedicated to Professor Jonas Kubilius on his 85th anniversary
Published in Lietuvos Matematikos Rinkinys, Vol. 47, No. 1, pp. 29–38, January–March, 2007. 相似文献
6.
Long Miao 《Bulletin of the Brazilian Mathematical Society》2007,38(4):585-594
Let
be a class of groups. A subgroup H of a group G is called
-s-supplemented in G, if there exists a subgroup K of G such that G = HK and K/K ∩ HG belongs to
where HG is the maximal normal subgroup of G which is contained in H. The main purpose of this paper is to study some subgroups of Fitting subgroup and generalized Fitting subgroup
-s-supplemented and some new criterions of p-nilpotency of finite groups are obtained.
*This research is supported by the grant of NSFC and TianYuan Fund of Mathematics of China (Grant #10626047). 相似文献
7.
Jorge J. Betancor Juan Carlos Fariña Teresa Martínez José Luis Torrea 《Israel Journal of Mathematics》2007,157(1):259-282
We study g-functions and Riesz transforms related to the Bessel operators
The method we use allows us to characterize the Banach spaces
for which these operators are bounded when acting on
-valued functions.
First and second authors were partially supported by Consejería de Educación, Gobierno de Canarias PI2003/068 and DGI grant
MTM2004-05878.
Third and fourth authors were partially supported by BFM grant 2002-04013-C02-02. 相似文献
8.
N. Ya. Medvedev 《Algebra and Logic》2005,44(3):197-204
A sufficient condition is given under which factors of a system of normal convex subgroups of a linearly ordered (l.o.) group are Abelian. Also, a sufficient condition is specified subject to which factors of a system of normal convex subgroups of an l.o. group are contained in a group variety
. In particular, for every soluble l.o. group G of solubility index n, n ⩾ 2, factors of a system of normal convex subgroups are soluble l.o. groups of solubility index at most n − 1. It is proved that the variety
of all lattice-ordered groups, approximable by linearly ordered groups, does not coincide with a variety generated by all soluble l.o. groups. It is shown that if
is any o-approximable variety of l-groups, and if every identity in the group signature is not identically true in
, then
contains free l.o. groups.Supported by FP “Universities of Russia” grant UR. 04. 01. 001.__________Translated from Algebra i Logika, Vol. 44, No. 3, pp. 355–367, May–June, 2005. 相似文献
9.
10.
We define the reduced minimum modulus
of a nonzero element a in a unital C
*-algebra
by
. We prove that
. Applying this result to
and its closed two side ideal
, we get that dist
,
and
for any
if RR
= 0, where
and
is the quotient homomorphism and
. These results generalize corresponding results in Hilbert spaces. 相似文献
11.
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
12.
Let
be a nondecreasing sequence of positive numbers and let l
1,α be the space of real sequences
for which
. We associate every sequence ξ from l
1,α with a sequence
, where ϕ(·) is a permutation of the natural series such that
, j ∈ ℕ. If p is a bounded seminorm on l
1,α and
, then
Using this equality, we obtain several known statements.
__________
Translated from Ukrains'kyi Matematychnyi Zhurnal, Vol. 57, No. 7, pp. 1002–1006, July, 2005. 相似文献
13.
Positive Solutions for Semipositone
<Emphasis Type="Italic">m</Emphasis>-point Boundary-value
Problems 总被引:7,自引:0,他引:7
Abstract
Let ξ
i
∈ (0, 1) with 0 <
ξ1 < ξ2 <
··· < ξ
m−2 < 1,
a
i
, b
i
∈ [0,∞) with
and
. We consider the
m-point boundary-value
problem
where f(x, y) ≥ −M, and M is a positive constant. We show the
existence and multiplicity of positive solutions by applying the
fixed point theorem in cones.
*Supported by the NSFC (10271095).
GG-110-10736-1003, NWNU-KJCXGC-212 and the Foundation of Major
Project of Science and Technology of Chinese Education
Ministry 相似文献
14.
Yu Can ZHU 《数学学报(英文版)》2007,23(9):1707-1718
In this paper, we introduce the concepts of q-Besselian frame and (p, σ)-near Riesz basis in a Banach space, where a is a finite subset of positive integers and 1/p+1/q = 1 with p 〉 1, q 〉 1, and determine the relations among q-frame, p-Riesz basis, q-Besselian frame and (p, σ)-near Riesz basis in a Banach space. We also give some sufficient and necessary conditions on a q-Besselian frame for a Banach space. In particular, we prove reconstruction formulas for Banach spaces X and X^* that if {xn}n=1^∞ C X is a q-Besselian frame for X, then there exists a p-Besselian frame {y&*}n=1^∞ belong to X^* for X^* such that x = ∑n=1^∞ yn^*(x)xn for all x ∈ X, and x^* =∑n=1^∞ x^*(xn)yn^* for all x^* ∈ X^*. Lastly, we consider the stability of a q-Besselian frame for the Banach space X under perturbation. Some results of J. R. Holub, P. G. Casazza, O. Christensen and others in Hilbert spaces are extended to Banach spaces. 相似文献
15.
T. V. Skrypnyk 《Theoretical and Mathematical Physics》2008,155(1):633-645
Using the R-operator on a Lie algebra
satisfying the modified classical Yang-Baxter equation, we define two sets of functions that mutually commute with respect
to the initial Lie-Poisson bracket on
. We consider examples of the Lie algebras
with the Kostant-Adler-Symes and triangular decompositions, their R-operators, and the corresponding two sets of mutually
commuting functions in detail. We answer the question for which R-operators the constructed sets of functions also commute
with respect to the R-bracket. We briefly discuss the Euler-Arnold-type integrable equations for which the constructed commutative
functions constitute the algebra of first integrals.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 155, No. 1, pp. 147–160, April, 2008. 相似文献
16.
Given any R-semimodule M equipped with a semitopology
we construct an N-protosummation
for M. If
satisfies certain properties, then a similar construction leads to an unconditional N-summation
for M, that is an N-summation for M equipped with the trivial prenorm MD over the N-summation (DN,D) for D. Conversely any N-protosummation
on M gives rise to a topology
. If both
and
satisfy a certain separation property, then
and
form a Galois connection.
Dedicated to my friend and collegue Nico Pumplün on the occasion of his 70th birthdayMathematics Subject Classifications (2000) 16Y60, 54A05. 相似文献
17.
For suitable positive integers n and k let m(n, k) denote the maximum number of edges in a graph of order n which has a unique k-factor. In 1964, Hetyei and in 1984, Hendry proved
for even n and
, respectively. Recently, Johann confirmed the following conjectures of Hendry:
for
and kn even and
for n = 2kq, where q is a positive integer. In this paper we prove
for
and kn even, and we determine m(n, 3). 相似文献
18.
The existence of infinitely many solutions of the following Dirichlet problem for p-mean curvature operator:
is considered, where Θ is a bounded domain in R
n
(n>p>1) with smooth boundary ∂Θ. Under some natural conditions together with some conditions weaker than (AR) condition, we prove that the above problem
has infinitely many solutions by a symmetric version of the Mountain Pass Theorem if
.
Supported by the National Natural Science Foundation of China (10171032) and the Guangdong Provincial Natural Science Foundation
(011606). 相似文献
19.
Eberhard MALKOWSKY M. MURSALEEN Suthep SUANTAI 《数学学报(英文版)》2007,23(3):521-532
Let p = (pk)k=0^∞ be a bounded sequence of positive reals, m C N and u be s sequence of nonzero terms. If x = (xk)k=0^∞ is any sequence of complex numbers we write Δ(m)x for the sequence of the m th order differences of x and Δu^(m)X = {x=(x)k=0^∞ uΔ(m)x ∈ X} for any set X of sequences. We determine the α-, β- and γ-duals of the sets Δμ^(m)X for X=co(p),c(p),l∞(p) and characterize some matrix transformations between these spaces Δ^(m)X. 相似文献