Displaying 2901 – 2920 of 4562

Showing per page

On the difference property of Borel measurable functions

Hiroshi Fujita, Tamás Mátrai (2010)

Fundamenta Mathematicae

If an atomlessly measurable cardinal exists, then the class of Lebesgue measurable functions, the class of Borel functions, and the Baire classes of all orders have the difference property. This gives a consistent positive answer to Laczkovich's Problem 2 [Acta Math. Acad. Sci. Hungar. 35 (1980)]. We also give a complete positive answer to Laczkovich's Problem 3 concerning Borel functions with Baire-α differences.

On the differentiability of certain saltus functions

Gerald Kuba (2011)

Colloquium Mathematicae

We investigate several natural questions on the differentiability of certain strictly increasing singular functions. Furthermore, motivated by the observation that for each famous singular function f investigated in the past, f’(ξ) = 0 if f’(ξ) exists and is finite, we show how, for example, an increasing real function g can be constructed so that g ' ( x ) = 2 x for all rational numbers x and g’(x) = 0 for almost all irrational numbers x.

On the Dirichlet problem for functions of the first Baire class

Jiří Spurný (2001)

Commentationes Mathematicae Universitatis Carolinae

Let be a simplicial function space on a metric compact space X . Then the Choquet boundary Ch X of is an F σ -set if and only if given any bounded Baire-one function f on Ch X there is an -affine bounded Baire-one function h on X such that h = f on Ch X . This theorem yields an answer to a problem of F. Jellett from [8] in the case of a metrizable set X .

On the distribution on the roots of polynomials

Francesco Amoroso, Maurice Mignotte (1996)

Annales de l'institut Fourier

Using classical results on conjugate functions, we give very short proofs of theorems of Erdös–Turán and Blatt concerning the angular distribution of the roots of polynomials. Then we study some examples.

On the dominance relation between ordinal sums of conjunctors

Susanne Saminger, Bernard De Baets, Hans De Meyer (2006)

Kybernetika

This contribution deals with the dominance relation on the class of conjunctors, containing as particular cases the subclasses of quasi-copulas, copulas and t-norms. The main results pertain to the summand-wise nature of the dominance relation, when applied to ordinal sum conjunctors, and to the relationship between the idempotent elements of two conjunctors involved in a dominance relationship. The results are illustrated on some well-known parametric families of t-norms and copulas.

On the double Lusin condition and convergence theorem for Kurzweil-Henstock type integrals

Abraham Racca, Emmanuel Cabral (2016)

Mathematica Bohemica

Equiintegrability in a compact interval E may be defined as a uniform integrability property that involves both the integrand f n and the corresponding primitive F n . The pointwise convergence of the integrands f n to some f and the equiintegrability of the functions f n together imply that f is also integrable with primitive F and that the primitives F n converge uniformly to F . In this paper, another uniform integrability property called uniform double Lusin condition introduced in the papers E. Cabral...

Currently displaying 2901 – 2920 of 4562