The compatible Grassmannian

E. Andruchow, E. Chiumiento, M. E. Di Iorio y Lucero

Let $A$ be a positive injective operator in a Hilbert space (\h, <,>), and denote by [,] the inner product defined by A: [f,g]=<Af,g>. A closed subspace $\s \subset \h$ is called A…