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Józef Marcinkiewicz (1910-1940) - on the centenary of his birth

Lech Maligranda (2011)

Banach Center Publications

Józef Marcinkiewicz’s (1910-1940) name is not known by many people, except maybe a small group of mathematicians, although his influence on the analysis and probability theory of the twentieth century was enormous. This survey of his life and work is in honour of the 100 t h anniversary of his birth and 70 t h anniversary of his death. The discussion is divided into two periods of Marcinkiewicz’s life. First, 1910-1933, that is, from his birth to his graduation from the University of Stefan Batory in Vilnius,...

Kempisty's theorem for the integral product quasicontinuity

Zbigniew Grande (2006)

Colloquium Mathematicae

A function f: ℝⁿ → ℝ satisfies the condition Q i ( x ) (resp. Q s ( x ) , Q o ( x ) ) at a point x if for each real r > 0 and for each set U ∋ x open in the Euclidean topology of ℝⁿ (resp. strong density topology, ordinary density topology) there is an open set I such that I ∩ U ≠ ∅ and | ( 1 / μ ( U I ) ) U I f ( t ) d t - f ( x ) | < r . Kempisty’s theorem concerning the product quasicontinuity is investigated for the above notions.

Korn's First Inequality with variable coefficients and its generalization

Waldemar Pompe (2003)

Commentationes Mathematicae Universitatis Carolinae

If Ω n is a bounded domain with Lipschitz boundary Ω and Γ is an open subset of Ω , we prove that the following inequality Ω | A ( x ) u ( x ) | p d x 1 / p + Γ | u ( x ) | p d n - 1 ( x ) 1 / p c u W 1 , p ( Ω ) holds for all u W 1 , p ( Ω ; m ) and 1 < p < , where ( A ( x ) u ( x ) ) k = i = 1 m j = 1 n a k i j ( x ) u i x j ( x ) ( k = 1 , 2 , ... , r ; r m ) defines an elliptic differential operator of first order with continuous coefficients on Ω ¯ . As a special case we obtain Ω u ( x ) F ( x ) + ( u ( x ) F ( x ) ) T p d x c Ω | u ( x ) | p d x , ( * ) for all u W 1 , p ( Ω ; n ) vanishing on Γ , where F : Ω ¯ M n × n ( ) is a continuous mapping with det F ( x ) μ > 0 . Next we show that ( * ) is not valid if n 3 , F L ( Ω ) and det F ( x ) = 1 , but does hold if p = 2 , Γ = Ω and F ( x ) is symmetric and positive definite in Ω .

Kurzweil-Henstock and Kurzweil-Henstock-Pettis integrability of strongly measurable functions

B. Bongiorno, Luisa Di Piazza, Kazimierz Musiał (2006)

Mathematica Bohemica

We study the integrability of Banach valued strongly measurable functions defined on [ 0 , 1 ] . In case of functions f given by n = 1 x n χ E n , where x n belong to a Banach space and the sets E n are Lebesgue measurable and pairwise disjoint subsets of [ 0 , 1 ] , there are well known characterizations for the Bochner and for the Pettis integrability of f (cf Musial (1991)). In this paper we give some conditions for the Kurzweil-Henstock and the Kurzweil-Henstock-Pettis integrability of such functions.

Kurzweil-Henstock type integral on zero-dimensional group and some of its applications

Valentin Skvortsov, Francesco Tulone (2008)

Czechoslovak Mathematical Journal

A Kurzweil-Henstock type integral on a zero-dimensional abelian group is used to recover by generalized Fourier formulas the coefficients of the series with respect to the characters of such groups, in the compact case, and to obtain an inversion formula for multiplicative integral transforms, in the locally compact case.

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