| In this thesis, we simulate the time evolution of quantum many-body systems and use comparisons to experimental data in order to learn more about the properties of nuclear matter and understand better the dynamical processes in central nuclear collisions. We further advance the development of a nonequilibrium Green's function description of both central nuclear collisions and Bose-Einstein Condensates.;First in the thesis, we determine the viscosity of nuclear matter by adjusting the in-medium nucleon-nucleon cross section (IMNNCS) in our BUU transport model until the simulation results match experimental data on nuclear stopping in central nuclear collisions at intermediate energies. Then we use that cross section to calculate the viscosity self-consistently. We also calculate the ratio of shear viscosity to entropy density to determine how close the system is to the proposed universal quantum lower limit.;Next, we use the same BUU transport model to isolate the protons emitted early in a central nuclear collision at intermediate energy, as predicted in the model, using a filter on high transverse momentum, and we show the effect on the source function. We predict a recontraction of protons at late times in the central collision of 112Sn+112Sn at 50 MeV/nucleon that results in a resurgence of emission of protons and show how to use the transverse momentum filter and the source function to test this prediction in experiment.;Next, we develop an early implementation of a more fully quantal transport model than the BUU equations, with our sights set on solving central nuclear collisions in 3D using nonequilibrium Green's functions. In our 1D, mean field, density matrix model, we demonstrate the initial state preparation and collision of 1D nuclear "slabs". With the aim of reducing the computational cost of the calculation, we show that we can neglect far off-diagonal elements in the density matrix without affecting the one-body observables.;Further, we describe a method of recasting the density matrix in a rotated coordinate system, enabling us to not only ignore the irrelevant matrix elements in the time evolution, but also avoid computing them completely, reducing the computational cost. As an added benefit, we find that the rotation allows us to partially decouple the position and momentum discretization, permitting access to arbitrary regimes of kinetic energy without altering the resolution and range of the 1D box in position space.;Finally, we exhibited the wide applicability of this density matrix approach by applying it to a system of 2000 ultracold 87Rb atoms in a Bose-Einstein condensate, as described by the Gross-Pitaevskii equation, successfully achieving a stable state in a harmonic oscillator trap. |
