Date of Award

January 2015

Degree Type


Degree Name

Doctor of Philosophy (PhD)


Physics & Astronomy

First Advisor

Denes Molnar

Committee Member 1

Andrew Hirsch

Committee Member 2

Martin Kruczenski

Committee Member 3

Wei Xie


The most widely used theoretical framework to model the early stages of a heavy-ion collision is viscous hydrodynamics. Comparing hydrodynamic simulations to heavy-ion data inevitably requires the conversion of the fluid to particles. This conversion, typically done in the Cooper-Frye formalism, is ambiguous for viscous fluids. In this thesis work, self-consistent phase space corrections are calculated by solving the linearized Boltzmann equation. These species-dependent solutions are contrasted with those obtained using the ad-hoc ``democratic Grad'' ansatz typically employed in the literature in which coefficients are independent of particle dynamics. Solutions are calculated analytically for a massless gas and numerically for the general case of a hadron resonance gas. For example, it is found that for a gas of massless particles interacting via isotropic, energy-independent 2 to 2 scatterings, the shear viscous corrections variationally prefer a momentum dependence close to p^3/2 rather than the quadratic dependence assumed in the Grad ansatz.