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1.
Let X and Y be Banach spaces. A set
(the space of all weakly compact operators from X into Y) is weakly equicompact if, for every bounded sequence (x
n) in X, there exists a subsequence (x
k(n)) so that (Txk(n)) is uniformly weakly convergent for T ∈ M. In this paper, the notion of weakly equicompact set is used to obtain characterizations of spaces X such that
X ↩̸ ℓ1, of spaces X such that B
X*
is weak* sequentially compact and also to obtain several results concerning to the weak operator and the strong operator
topologies. As another application of weak equicompactness, we conclude a characterization of relatively compact sets in
when this space is endowed with the topology of uniform convergence on the class of all weakly null sequences. Finally, we
show that similar arguments can be applied to the study of uniformly completely continuous sets.
Received: 5 July 2006 相似文献
2.
“Setting” n-Opposition 总被引:1,自引:1,他引:0
Régis Pellissier 《Logica Universalis》2008,2(2):235-263
Our aim is to show that translating the modal graphs of Moretti’s “n-opposition theory” (2004) into set theory by a suited device, through identifying logical modal formulas with appropriate
subsets of a characteristic set, one can, in a constructive and exhaustive way, by means of a simple recurring combinatory,
exhibit all so-called “logical bi-simplexes of dimension n” (or n-oppositional figures, that is the logical squares, logical hexagons, logical cubes, etc.) contained in the logic produced
by any given modal graph (an exhaustiveness which was not possible before). In this paper we shall handle explicitly the classical
case of the so-called 3(3)-modal graph (which is, among others, the one of S5), getting to a very elegant tetraicosahedronal
geometrisation of this logic.
相似文献
3.
We showed that any reversible Finsler metric with positive constant flag curvature must be Riemannian.
Received: 18 August 2008 相似文献
4.
Stevo Stević 《Mediterranean Journal of Mathematics》2008,5(1):61-76
In this paper we investigate harmonic Hardy-Orlicz and Bergman-Orlicz b
φ,α
(B) spaces, using an identity of Hardy-Stein type. We also extend the notion of the Lusin property by introducing (φ, α)-Lusin property with respect to a Stoltz domain. The main result in the paper is as follows: Let be a nonnegative increasing convex function twice differentiable on (0, ∞), and u a harmonic function on the unit ball B in . Then the following statements are equivalent:
相似文献
(a) | . |
(b) | . |
(c) | u has (φ, α)-Lusin property with respect to a Stoltz domain with half-angle β, for any . |
(d) | u has (φ, α)-Lusin property with respect to a Stoltz domain with half-angle β, for some . |
5.
Let G be a finite group, let A be a group of automorphisms of G and let CG(A) denote the subgroup of fixed points of A in G. If the order of CG(A) is coprime to the number of orbits of A in G, then CG(A) is contained in the autocommutator subgroup [G, A]. The notion of class-avoiding automorphism is used to extend theorems of J. Thompson and P. Rowley.
Received: 3 November 2008, Revised: 1 December 2008 相似文献
6.
Piotr Jucha 《Archiv der Mathematik》2008,90(6):559-571
We discuss the properties of the Wu pseudometric and present counterexamples for its upper semicontinuity that answers the
question posed by Jarnicki and Pflug. We also give formulae for the Wu pseudometric in elementary Reinhardt domains.
Received: 12 September 2007 相似文献
7.
In this paper, we investigate several interesting subordination results of some classes of analytic functions defined by means
of the Al-Oboudi–Al-Amoudi operator.
Received: 15 August 2008, Revised: 19 November 2008 相似文献
8.
Massimo Grossi 《NoDEA : Nonlinear Differential Equations and Applications》2005,12(2):227-241
Let Ω be a smooth bounded domain of
with N ≥ 5. In this paper we prove, for ɛ > 0 small, the nondegeneracy of the solution of the problem
under a nondegeneracy condition on the critical points of the Robin function. Our proof uses different techniques with respect
to other known papers on this topic. 相似文献
9.
We prove that the so-called Smoluchowski-Kramers approximation holds for a class of partial differential equations perturbed
by a non-Gaussian noisy term. Namely, we show that the solution of the one-dimensional semi-linear stochastic damped wave
equations
, u(0) = u0, ut (0) = v0, endowed with Dirichlet boundary conditions, converges as the parameter μ goes to zero to the solution of the semi-linear
stochastic heat equation
, u(0) = u0, endowed with Dirichlet boundary conditions.
Dedicated to Giuseppe Da Prato on the occasion of his 70th birthday 相似文献
10.
Adimurthi Jacques Giacomoni 《NoDEA : Nonlinear Differential Equations and Applications》2005,12(1):1-20
This paper deals with the existence and the behaviour of global connected branches of positive solutions of the problem
We consider a function h which is smooth and changes sign. 相似文献
11.
Zineb Mimouni René Limage 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,60(3):569-574
Within the framework of the study of the fibrillation mechanism in an electrorheological (ER) suspension, this work presents
a comparison between the self similar solutions when the kernel is Ki,j ~ (i−1 + j−1) and the behaviour of the chains growth. Till now, the field induced chains formation has only been studied by numerical
or experimental methods. The work of Fournier and Lauren?ot (Communications in Mathematical Physics 256 2005) on the Smoluchowski’s
equation allows us to present an analytical solution for the field induced pearl chains in a colloidal ER suspension.
René Limage: Chercheur indépendant, dipl?mé de l’Université de Liége. 相似文献
12.
Moshe Kamensky 《Selecta Mathematica, New Series》2009,15(2):295-341
The motivation for this paper is to extend the known model-theoretic treatment of differential Galois theory to the case of
linear difference equations (where the derivative is replaced by an automorphism). The model-theoretic difficulties in this case arise from
the fact that the corresponding theory ACFA does not eliminate quantifiers. We therefore study groups of restricted automorphisms,
preserving only part of the structure. We give conditions for such a group to be (infinitely) definable, and when these conditions
are satisfied we describe the definition of the group and the action explicitly.
We then examine the special case when the theory in question is obtained by enriching a stable theory with a generic automorphism.
Finally, we interpret the results in the case of ACFA, and explain the connection of our construction with the algebraic theory
of Picard–Vessiot extensions.
The only model-theoretic background assumed is the notion of a definable set.
相似文献
13.
Allen L. Mann 《Logica Universalis》2008,2(2):265-275
IFG logic is a variant of the independence-friendly logic of Hintikka and Sandu. We answer the question: “Which IFG-formulas
are equivalent to ordinary first-order formulas?” We use the answer to prove the ordinary cylindric set algebra over a structure
can be embedded into a reduct of the IFG-cylindric set algebra over the structure.
相似文献
14.
Joseph Lehec 《Archiv der Mathematik》2009,92(1):89-94
We give a direct proof of a functional Santaló inequality due to Fradelizi and Meyer. This provides a new proof of the Blaschke-Santaló
inequality. The argument combines a logarithmic form of the Prékopa-Leindler inequality and a partition theorem of Yao and
Yao.
Received: 21 August 2008 相似文献
15.
Let
We show that for every function
satisfying the conditional equation
either there exists a solution
of the Goab-Schinzel equation
such that
(i.e., f(x) = g(x) for
) or there is x0 > 0 with f(x0) < –1 and f(x) = 0 for x x0 . In particular we determine the solutions
of the conditional equation that are continuous at a point, Lebesgue measurable or Baire measurable (i.e., have the Baire property). In this way we solve some problems raised by the first author.Received: 2 March 2004 相似文献
0,{\text{ then }}f(x + f(x)y) = f(x)f(y) $$ " align="middle" vspace="20%" border="0"> |
16.
17.
Josef Daněček Eugen Viszus 《NoDEA : Nonlinear Differential Equations and Applications》2009,16(2):189-211
We discuss the interior C
0,γ-everywhere regularity for minimizers of quasilinear functionals of the type
where VMO dependence on the variable x and continuous dependence on the variable u are supposed.
J. Daněček was supported by the research project MSM 0021630511, E. Viszus was supported by the research project Slovak Grant
Agency No.1/0098/08. 相似文献
18.
19.
20.
Universal Laurent series where the universal approximation is valid on the boundary of the multiple connected open Ω appears
for the first time in [2]. We show that it is possible to demand universal approximation only to a part of the boundary while
on the remaining part the universal function can be smooth.
Received: 29 May 2007 相似文献