Equations, State, and Lattices of Infinite-Dimensional Hilbert Spaces

We provide several new result on quantum state space, on the lattice of subspacesof an infinite-dimensional Hilbert space, and on infinite-dimensional Hilbert spaceequations as well as on connections between them. In particular, we obtainan n-variable generalized orthoarguesian equation which holds in anyinfinite-dimensional Hilbert space. Then we strengthen Godowski's equationsas well ass the orthomodularity hold. We also prove that all six- and four-variableorthoarguesian equation presented in the literature can be reduced to newfour- and three-variable ones, respectively, and that Mayet's examples follow fromGodowski's equations. To make a breakthrough in testing these massive equations,we designed several novel algorithms for generating Greechie diagrams with anarbitrary number of blocks and atoms (currently testing with up to 50) and forautomated checking of equations on them. A way of obtaining complexinfinite-dimensional Hilbert space from the Hilbert lattice equipped with several additionalconditions and without invoking the notion of state is presented. Possiblerepercussions of the results on quantum computing problems are discussed.