Displaying 41 – 60 of 216

Showing per page

On isomorphisms of some Köthe function F-spaces

Violetta Kholomenyuk, Volodymyr Mykhaylyuk, Mikhail Popov (2011)

Open Mathematics

We prove that if Köthe F-spaces X and Y on finite atomless measure spaces (ΩX; ΣX, µX) and (ΩY; ΣY; µY), respectively, with absolute continuous norms are isomorphic and have the property lim μ ( A ) 0 μ ( A ) - 1 1 A = 0 (for µ = µX and µ = µY, respectively) then the measure spaces (ΩX; ΣX; µX) and (ΩY; ΣY; µY) are isomorphic, up to some positive multiples. This theorem extends a result of A. Plichko and M. Popov concerning isomorphic classification of L p(µ)-spaces for 0 < p < 1. We also provide a new class of F-spaces...

On Jackson type inequality in Orlicz classes.

Konstantin Runovski (2001)

Revista Matemática Complutense

It is shown that Jackson type inequality fails in the Orlicz classes φ(L) if φ(x) differs essentially from a power function of any order.

On James and Jordan-von Neumann constants and the normal structure coefficient of Banach spaces

Mikio Kato, Lech Maligranda, Yasuji Takahashi (2001)

Studia Mathematica

Some relations between the James (or non-square) constant J(X) and the Jordan-von Neumann constant C N J ( X ) , and the normal structure coefficient N(X) of Banach spaces X are investigated. Relations between J(X) and J(X*) are given as an answer to a problem of Gao and Lau [16]. Connections between C N J ( X ) and J(X) are also shown. The normal structure coefficient of a Banach space is estimated by the C N J ( X ) -constant, which implies that a Banach space with C N J ( X ) -constant less than 5/4 has the fixed point property.

On L 1 Space Formed by Complex-Valued Partial Functions

Yasushige Watase, Noboru Endou, Yasunari Shidama (2012)

Formalized Mathematics

In this article, we formalized L1 space formed by complexvalued partial functions [11], [15]. The real-valued case was formalized in [22] and this article is its generalization.

On L 1 Space Formed by Real-Valued Partial Functions

Yasushige Watase, Noboru Endou, Yasunari Shidama (2008)

Formalized Mathematics

This article contains some definitions and properties refering to function spaces formed by partial functions defined over a measurable space. We formalized a function space, the so-called L1 space and proved that the space turns out to be a normed space. The formalization of a real function space was given in [16]. The set of all function forms additive group. Here addition is defined by point-wise addition of two functions. However it is not true for partial functions. The set of partial functions...

On L p Space Formed by Real-Valued Partial Functions

Yasushige Watase, Noboru Endou, Yasunari Shidama (2010)

Formalized Mathematics

This article is the continuation of [31]. We define the set of Lp integrable functions - the set of all partial functions whose absolute value raised to the p-th power is integrable. We show that Lp integrable functions form the Lp space. We also prove Minkowski's inequality, Hölder's inequality and that Lp space is Banach space ([15], [27]).

On limiting embeddings of Besov spaces

V. I. Kolyada, A. K. Lerner (2005)

Studia Mathematica

We investigate the classical embedding B p , θ s B q , θ s - n ( 1 / p - 1 / q ) . The sharp asymptotic behaviour as s → 1 of the operator norm of this embedding is found. In particular, our result yields a refinement of the Bourgain, Brezis and Mironescu theorem concerning an analogous problem for the Sobolev-type embedding. We also give a different, elementary proof of the latter theorem.

Currently displaying 41 – 60 of 216