Evolution speed of open quantum dynamics Dorje Brody (U. Surrey) The space of density matrices is embedded in a Euclidean space to deduce the dynamical equation satisfied by the state of an open quantum system. The Euclidean norm is used to obtain an explicit expression for the speed of the evolution of the state. The unitary contribution to the evolution speed is given by the modified skew information of the Hamiltonian, while the radial component of the evolution speed, connected to the rate at which the purity of the state changes, is shown to be determined by the modified skew information of the Lindblad operators. An open-system analogue of the quantum navigation problem is posed. Properties of the evolution speed are examined further through example systems, including a PT-symmetric open quantum system. (Based on joint work with B. Longstaff [1].) [1] D.C. Brody and B. Longstaff, arXiv:1906.04766