# At the Interface: Gravitational Waves as Tools to Test Quantum Gravity and Probe the Astrophysical Universe

Open Access

- Graduate Program:
- Physics
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- May 08, 2008
- Committee Members:
- Benjamin J Owen, Committee Chair
- Stephon H S Alexander, Committee Member
- Pablo Laguna, Committee Member
- Steinn Sigurdsson, Committee Member

- Keywords:
- test
- black hole
- string theory
- gravitational waves
- recoil velocity
- post-Newtonian

- Abstract:
- This thesis discusses gravitational waves from binary systems of compact objects and their role as probes of quantum gravity and the astrophysical universe. Part A deals with the modeling of the merger phase of binary systems through numerical relativity, concentrating on the initial data problem. In particular, Chapters 2 and 3 present an improved method to construct such data for non-spinning black hole binaries by combining post-Newtonian and black hole perturbation theory via matched asymptotic expansions. Chapter 4 studies a class of transition functions that allow such gluing of asymptotically-matched approximate 4-metrics. Chapter 5 discusses how to extend the analysis of the previous chapters to spinning black holes, by studying vacuum perturbations of the Kerr metric via the modified Chrzanowski procedure. Part B focuses on astrophysical applications of gravitational waves from binary black hole inspirals and mergers. Chapters 6 and 7 construct estimates of the recoil velocity a merger remnant acquires for circular and eccentric inspirals of non-spinning black holes. These estimates are calculated by combining techniques from black hole perturbation theory in the close-limit approximation and post-Newtonian theory. Chapter 8 studies relativistic burst signals, namely relativistic sling-shot orbits of massive compact objects around supermassive black holes. In particular, this chapter deals with the possibility of extracting the spin parameter of the central object through a gravitational wave detection of such gravitational wave bursts. Part C concentrates on tests of string theory and loop quantum gravity with gravitational experiments. Chapters 9 considers the possibility of using solar-system experiments to test Chern-Simons gravity - an ubiquitous correction to general relativity that emerges as the low-energy limit of string theory and possibly loop quantum gravity. Chapter 10 studies spinning black holes in Chern-Simons gravity, while Chapter 11 is concerned with perturbations of non-spinning black holes in this theory. These chapters suggest that a gravitational wave detection could be used to test the Chern-Simons correction, which is discussed in Chapter 12.