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On vector measures

Corneliu Constantinescu (1975)

Annales de l'institut Fourier

Let be the Banach space of real measures on a σ -ring R , let ' be its dual, let E be a quasi-complete locally convex space, let E ' be its dual, and let μ be an E -valued measure on R . If is shown that for any θ ' there exists an element θ d μ of E such that x ' μ , θ = θ d μ , x ' for any x ' E ' and that the map θ θ d μ : ' E is order continuous. It follows that the closed convex hull of μ ( R ) is weakly compact.

On Vitali-Hahn-Saks-Nikodym type theorems

Barbara T. Faires (1976)

Annales de l'institut Fourier

A Boolean algebra 𝒜 has the interpolation property (property (I)) if given sequences ( a n ) , ( b m ) in 𝒜 with a n b m for all n , m , there exists an element b in 𝒜 such that a n b b n for all n . Let 𝒜 denote an algebra with the property (I). It is shown that if ( μ n : 𝒜 X ) ( X a Banach space) is a sequence of strongly additive measures such that lim n μ n ( a ) exists for each a 𝒜 , then μ ( a ) = lim n μ n ( a ) defines a strongly additive map from 𝒜 to X and the μ n ' s are uniformly strongly additive. The Vitali-Hahn-Saks (VHS) theorem for strongly additive X -valued measures defined...

On Weak Compactness and Lower Closure Results for Pettis Integrable (Multi)Functions

Erik J. Balder, Anna Rita Sambucini (2004)

Bulletin of the Polish Academy of Sciences. Mathematics

In [4, 5, 7] an abstract, versatile approach was given to sequential weak compactness and lower closure results for scalarly integrable functions and multifunctions. Its main tool is an abstract version of the Komlós theorem, which applies to scalarly integrable functions. Here it is shown that this same approach also applies to Pettis integrable multifunctions, because the abstract Komlós theorem can easily be extended so as to apply to generalized Pettis integrable functions. Some results in the...

On Weakly Measurable Functions

Szymon Żeberski (2005)

Bulletin of the Polish Academy of Sciences. Mathematics

We show that if T is an uncountable Polish space, 𝓧 is a metrizable space and f:T→ 𝓧 is a weakly Baire measurable function, then we can find a meagre set M ⊆ T such that f[T∖M] is a separable space. We also give an example showing that "metrizable" cannot be replaced by "normal".

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