# Descriptions of quadratic plus linear operators which preserve pure states of the quantum system

@inproceedings{Saburov2013DescriptionsOQ, title={Descriptions of quadratic plus linear operators which preserve pure states of the quantum system}, author={Mansoor Saburov}, year={2013} }

As we knew, a mathematical formalism of a quantum mechanics says that any quantum system is
identified with some finite- or infinite-dimensional Hilbert space; pure states correspond to vectors
of norm 1; observables are self-adjoint operators on the space of states. Thus the set of all pure
states corresponds to the unit sphere in the Hilbert space [1-2]. It is of interest to describe all linear
or nonlinear operators which preserve the pure states of the system. In the linear case, it is… CONTINUE READING