2015/12/03 by Mark Pankov, Pankov, Mark
Mathematics · Computer Science · #Advanced Combinatorial Mathematics #Advanced Graph Theory Research #Advanced Algebra and Logic
paper · pdf · doi:10.48550/arxiv.1512.01007
Let H be an infinite-dimensional complex Hilbert space and let \mathcal L(H) be the logic formed by all closed subspaces of H. For every natural k we denote by \mathcal Gk(H) the Grassmannian consisting of k-dimensional subspaces. An orthogonal apartment of \mathcal Gk(H) is the set consisting of all k-dimensional subspaces spanned by subsets of a certain orthogonal base of H. Orthogonal apartments can be characterized as maximal sets of mutually compatible elements of \mathcal Gk(H). We show that every bijective transformation f of \mathcal Gk(H) such that f and f-1 send orthogonal apartments to orthogonal apartments (in other words, f preserves the compatibility relation in both directions) can be uniquely extended to an automorphism of \mathcal L(H).