The success of a genetic optimization algorithm in continuous parameter space depends on the recombination (crossover) operators that it uses. In this paper we consider a wide spectrum of such operators within a unified framework and study their relative importance in the search process. We consider four basic types recombination operators which cover the relevant exploration potential of a continuous space: Interpolation, Extrapolation, Exchange and Mutation. Each of these basic types may have several variants. We characterize the various operators and their variants by their spatial sampling properties and examine their contributions to the search by applying different mixtures of the operators in several benchmark problems. The results suggest that the optimal mixture of operators may depend on the problem. But, in general, all basic types are needed for efficient optimization.

A brief sketch of the accomplishments made in the past year is given for the following: {epsilon} expansion analysis of weak first-order transitions in the cubic anisotropy model; the non-Abelian Debye screening length beyond leading order; electric-magnetic duality and the heavy quark potential; ice water vapor interface; groups in cold dark matter simulations; Compton scattering on black body photons; nuclear reaction rates in a plasma; comparison of jets from electron-positron interactions and hadronic collisions; the energy-energy correlation in perturbation theory; CPT violation search in the kaon system; regularization of chiral gauge theories; dynamical supersymmetry breaking; electroweak baryogenesis; quenched chiral perturbation theory for heavy-light mesons; testing the chiral behavior of the hadron spectrum; hadron spectrum with Wilson fermions; quenched chiral perturbation theory for baryons; matrix elements of 4-fermion operators with quenched Wilson fermions; classical preheating and decoherence; reheating and thermalization in a simple scalar model; and from quantum field theory to hydrodynamics: transport coefficients and effective kinetic theory.