title: Correlation functions in quantized Hamilton dynamics and quantal cumulant dynamics.
abstract: Quantized Hamilton dynamics (QHD) [O. V. Prezhdo and Y. V. Pereverzev, J. Chem. Phys. 113, 6557 (2000)] and quantal cumulant dynamics (QCD) [Shigeta et al., J. Chem. Phys. 125, 244102 (2006)] are used to obtain a semiclassical description of two-time correlation functions (CFs). Generally, lower-order CFs couple to higher-order CFs. The infinite hierarchy is terminated by a closure, which neglects higher-order irreducible correlators and provides an efficient approximation to quantum mechanics. The approach is illustrated with a simple nonlinear system, for which the real part of the classical CF continues a perfect oscillation and the imaginary part is identically zero. At little computational expense, the second-order QHD/QCD approximation reproduces the real and imaginary parts of the quantum-mechanical CF.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
authors.forename: Yuriy V
authors.initials: YV
authors.lastname: Pereverzev
authors.forename: Andrey
authors.initials: A
authors.lastname: Pereverzev
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Shigeta
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Prezhdo