Award Date


Degree Type


Degree Name

Doctor of Philosophy (PhD)

First Committee Member

Stephen Lepp

Number of Pages



The purpose of this work is to perform a quantum mechanical calculation of the collisional state-to-state cross sections for H-H2 required for astrophysical modeling. Previous quantum and semi-classical cooling rates computed from cross sections have shown unexplained discrepancies. This attempts to clarify the situation and provide reliable cross sections to the astrophysical community. As a side benefit of this calculation geometric phase effects in the H-H2 collision dynamics are investigated at higher energies than previously attempted. Cooling is critical to the formation of the first objects formed in the early universe, and other diverse phenomenon of interest to astrophysics. For instance, in order to collapse into objects, the gravitational potential energy of primordial density fluctuations must be radiated away. The most abundant element in the universe is hydrogen, and cooling processes involving hydrogen are important in several contexts.


Astrophysics; Calculation; Collisional; Cross; Cross Section; Hydrogen; Hydrogen-hydrogen Collisions; Mechanical; Quantum; Section

Controlled Subject

Astronomy; Chemistry, Physical and theoretical; Nuclear physics

File Format


File Size

3.55 MB

Degree Grantor

University of Nevada, Las Vegas




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