Abstract
If (Ω, Σ, µ) is a probability space and X a Banach space, a theorem concerning sequences of X-valued random elements which do not converge to zero is applied to show from a common point of view that the F-normed space \( L_p (\mu ,X) \) of all classes of X-valued random variables, as well as the p-normed space L p (µ, X) of all X-valued p-integrable random variables with 0 < p < 1 and the space \( P_1 (\mu ,X) \) of the µ-measurable X-valued Pettis integrable functions, all contain a copy of \( c_0 \) if and only if X does. We also show that if is a noncompact hemicompact topological space, then the Banach space \( C_0 (\Omega ) \) of all scalarly valued continuous functions defined on vanishing at infinity, equipped with the supremum-norm, contains a norm-one complemented copy of \( c_0 \) .
Resumen
Si (Ω, Σ, µ) es un espacio de probabilidad y X un espacio de Banach, aplicamos un teorema sobre sucesiones de variables aleatorias con valores en X que no convergen a cero para demostrar, desde un punto de vista común, que el espacio F-normado \( L_p (\mu ,X) \) de las variables aleatorias p-integrables X-valoradas, con 0 < p < 1, y el espacio \( P_1 (\mu ,X) \) de las funciones X-valoradas µ-medibles y Pettis integrables, todos ellos contienen una copia de \( c_0 \) si y sólo si X también la contiene. Asimismo probamos que si Ω es un espacio topológico hemicompacto no compacto, el espacio de Banach \( C_0 (\Omega ) \) de las funciones continuas con valores escalares definidas en Ω que se anulan en el infinito, equipado con la norma supremo, contiene una copia de c 0 norma-uno complementada.
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Ferrando, J.C. On copies of \( c_0 \) in some function spaces. Rev. R. Acad. Cien. Serie A. Mat. 103, 49–54 (2009). https://doi.org/10.1007/BF03191832
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DOI: https://doi.org/10.1007/BF03191832
Keywords
- Banach space
- copy of c 0
- vector-valued random element
- F-norm
- p-norm
- space L p (µ, X) with
- 0≤ p<1
- space P 1(µ, X)
- hemicompact space
- space C 0(Ω)