Displaying 61 – 80 of 104

Showing per page

Monotone coefficients and monotonicity of Orlicz spaces.

Yanming Lü, Junming Wang, Tingfu Wang (1999)

Revista Matemática Complutense

The criteria for uniform monotonicity, locally uniformly monotonicity and monotonicity of of Orlicz spaces with Luxemburg and Orlicz norms are given. The monotone coefficients of a point and of the spaces are computed.

Monotone substochastic operators and a new Calderón couple

Karol Leśnik (2015)

Studia Mathematica

An important result on submajorization, which goes back to Hardy, Littlewood and Pólya, states that b ⪯ a if and only if there is a doubly stochastic matrix A such that b = Aa. We prove that under monotonicity assumptions on the vectors a and b the matrix A may be chosen monotone. This result is then applied to show that ( L p ˜ , L ) is a Calderón couple for 1 ≤ p < ∞, where L p ˜ is the Köthe dual of the Cesàro space C e s p ' (or equivalently the down space L p ' ). In particular, ( L ¹ ˜ , L ) is a Calderón couple, which gives a...

Monotonicity in Banach function spaces

Sinnamon, Gord (2007)

Nonlinear Analysis, Function Spaces and Applications

This paper is an informal presentation of material from [28]–[34]. The monotone envelopes of a function, including the level function, are introduced and their properties are studied. Applications to norm inequalities are given. The down space of a Banach function space is defined and connections are made between monotone envelopes and the norms of the down space and its dual. The connection is shown to be particularly close in the case of universally rearrangement invariant spaces. Next, two equivalent...

Montel and reflexive preduals of spaces of holomorphic functions on Fréchet spaces

Christopher Boyd (1993)

Studia Mathematica

For U open in a locally convex space E it is shown in [31] that there is a complete locally convex space G(U) such that G ( U ) i ' = ( ( U ) , τ δ ) . Here, we assume U is balanced open in a Fréchet space and give necessary and sufficient conditions for G(U) to be Montel and reflexive. These results give an insight into the relationship between the τ 0 and τ ω topologies on ℋ (U).

Mosco convergence of sequences of homogeneous polynomials.

J. Ferrera (1998)

Revista Matemática Complutense

In this paper we give a characterization of uniform convergence on weakly compact sets, for sequences of homogeneous polynomials in terms of the Mosco convergence of their level sets. The result is partially extended for holomorphic functions. Finally we study the relationship with other convergences.

Multi-dimensional Fejér summability and local Hardy spaces

Ferenc Weisz (2009)

Studia Mathematica

It is proved that the multi-dimensional maximal Fejér operator defined in a cone is bounded from the amalgam Hardy space W ( h p , ) to W ( L p , ) . This implies the almost everywhere convergence of the Fejér means in a cone for all f W ( L , ) , which is larger than L ( d ) .

Multilinear Fourier multipliers with minimal Sobolev regularity, I

Loukas Grafakos, Hanh Van Nguyen (2016)

Colloquium Mathematicae

We find optimal conditions on m-linear Fourier multipliers that give rise to bounded operators from products of Hardy spaces H p k , 0 < p k 1 , to Lebesgue spaces L p . These conditions are expressed in terms of L²-based Sobolev spaces with sharp indices within the classes of multipliers we consider. Our results extend those obtained in the linear case (m = 1) by Calderón and Torchinsky (1977) and in the bilinear case (m = 2) by Miyachi and Tomita (2013). We also prove a coordinate-type Hörmander integral condition...

Multiplication of convex sets in C(K) spaces

José Pedro Moreno, Rolf Schneider (2016)

Studia Mathematica

Let C(K) denote the Banach algebra of continuous real functions, with the supremum norm, on a compact Hausdorff space K. For two subsets of C(K), one can define their product by pointwise multiplication, just as the Minkowski sum of the sets is defined by pointwise addition. Our main interest is in correlations between properties of the product of closed order intervals in C(K) and properties of the underlying space K. When K is finite, the product of two intervals in C(K) is always an interval....

Multiplication operators on L ( L p ) and p -strictly singular operators

William Johnson, Gideon Schechtman (2008)

Journal of the European Mathematical Society

A classification of weakly compact multiplication operators on L ( L p ) , 1<p< , i s g i v e n . T h i s a n s w e r s a q u e s t i o n r a i s e d b y S a k s m a n a n d T y l l i i n 1992 . T h e c l a s s i f i c a t i o n i n v o l v e s t h e c o n c e p t o f p - s t r i c t l y s i n g u l a r o p e r a t o r s , a n d w e a l s o i n v e s t i g a t e t h e s t r u c t u r e o f g e n e r a l p - s t r i c t l y s i n g u l a r o p e r a t o r s o n Lp . T h e m a i n r e s u l t i s t h a t i f a n o p e r a t o r T o n Lp , 1<p<2 , i s p - s t r i c t l y s i n g u l a r a n d T|X i s a n i s o m o r p h i s m f o r s o m e s u b s p a c e X o f Lp , t h e n X e m b e d s i n t o Lr f o r a l l r<2 , b u t X n e e d n o t b e i s o m o r p h i c t o a H i l b e r t s p a c e . It is also shown that if T is convolution by a biased coin on L p of the Cantor group, 1 p < 2 , and T | X is an isomorphism for some reflexive subspace X of L p , then X is isomorphic to a Hilbert space. The case p = 1 answers a question asked by Rosenthal in 1976.

Currently displaying 61 – 80 of 104