An Elementary Proof of Douglas′ Theorem on Contractive Projections on L1-Spaces

Constructing an Elementary Measure on a

Constructing an Elementary Measure on a Space of Projections

✍ Peter K Friz; James C Robinson 📂 Article 📅 2002 🏛 Elsevier Science 🌐 English ⚖ 108 KB

Bypassing much theory from integral geometry, we construct an elementary measure on a space whose elements can represent rank k orthogonal projections in N . By replacing the Grassmannian G N k with a simple product space k j=1 S N-1 we are able to reproduce certain important features of the nontriv