"The famous Gleason's Theorem gives a characterization of states on lattices of subspaces of Hilbert spaces. The attempts to simplify its proof have led to easy proofs of some consequences, mainly the non-existence of hidden variables (dispersion-free states). Here we simplify some of them. We also formulate related open problems concerning spaces with rational coordinates and group-valued measures."@en . "Mathematical questions related to non-existence of hidden variables" . "[7F1606CD3C31]" . "Mathematical questions related to non-existence of hidden variables"@en . . . . "2008-08-24+02:00"^^ . "1"^^ . "000265432200017" . "The famous Gleason's Theorem gives a characterization of states on lattices of subspaces of Hilbert spaces. The attempts to simplify its proof have led to easy proofs of some consequences, mainly the non-existence of hidden variables (dispersion-free states). Here we simplify some of them. We also formulate related open problems concerning spaces with rational coordinates and group-valued measures." . "Mathematical questions related to non-existence of hidden variables" . "P(GA201/07/1051)" . . . "New York" . "American Institute of Physics" . . "0094-243X" . . . . . . "21230" . . . "Gleason's Theorem; Bell inequalities; Bell's Geometrical Lemma; Piron's Geometrical Lemma; Hilbert space; hidden variable; dispersion-free state; two-valued state; Kochen-Specker theorem; group-valued measure"@en . "978-0-7354-0636-0" . . . "RIV/68407700:21230/09:00178048!RIV11-GA0-21230___" . "V\u00E4xj\u00F6" . . . . . "Mathematical questions related to non-existence of hidden variables"@en . "Navara, Mirko" . "8"^^ . "RIV/68407700:21230/09:00178048" . "1"^^ . "Foundations of Probability and Physics - 5" . . . "324946" . . .