Projections 𝑃 on 𝐶=𝐶[-1,1] which interpolate at dim(𝑃(𝐶)) or more points

Yang, Chengmin

doi:10.1090/S0002-9939-1992-1089415-4

Projections $P$ on $C=C[-1,1]$ which interpolate at $\dim (P(C))$ or more points
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by Chengmin Yang

Proc. Amer. Math. Soc. 115 (1992), 669-676

DOI: https://doi.org/10.1090/S0002-9939-1992-1089415-4

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Abstract:

Let $V$ be an $n$ dimensional subspace of $C[ - 1,1]$. This paper gives a necessary and sufficient condition for a bounded linear projection $P$ from $C[ - 1,1]$ onto $V$ to have the property that $Pf$ interpolates $f$ at $n$ or more points for any $f \in C[ - 1,1]$.

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