Computational developments for ab initio manybody theory
Quantum manybody physics is the body of knowledge which studies systems of many interacting particles and the mathematical framework for calculating properties of these systems. Methods in manybody physics which use a first principles approach to solving the manybody Schrodinger equation are referred to as ab initio methods, and provide approximate solutions which are systematically improvable. Coupled cluster theory is an ab initio quantum manybody method which has been shown to provide accurate calculations of ground state energies for a wide range of systems in quantum chemistry and nuclear physics. Calculations of physical properties using ab initio manybody methods can be computationally expensive, requiring the development of efficient data structures, algorithms and techniques in highperformance computing to achieve numerical accuracy.Many physical systems of interest are difficult or impossible to measure experimentally, and so are reliant on predictive and accurate calculations from manybody theory. Neutron stars in particular are difficult to collect observational data for, but simulations of infinite nuclear matter can provide key insights to the internal structure of these astronomical objects. The main focus of this thesis is the development of a large and versatile coupled cluster program which implements a sparse tensor storage scheme and efficient tensor contraction algorithms. A distributed memory data structure for these large, sparse tensors is used so that the code can run in a highperformance computing setting, and can thus handle the computational challenges of infinite nuclear matter calculations using large basis sets. By validating these data structures and algorithms in the context of coupled cluster theory and infinite nuclear matter, they can be applied to a wide range of manybody methods and physical systems.
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Electronic Theses & Dissertations
 Copyright Status
 In Copyright
 Material Type

Theses
 Authors

Lietz, Justin Gage
 Thesis Advisors

HjorthJensen, Morten
 Committee Members

Bogner, Scott
O'Shea, Brian
Gade, Alex
Bazavov, Alexei
 Date
 2019
 Program of Study

Physics  Doctor of Philosophy
 Degree Level

Doctoral
 Language

English
 Pages
 xiii, 194 pages
 ISBN

9781085617277
1085617270
 Permalink
 https://doi.org/doi:10.25335/hgh5p721