Citation
Lovelace, Geoffrey Mark (2007) Topics in gravitationalwave physics. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd05232007115433
Abstract
Together with ongoing experimental efforts to detect gravitational waves, several fronts of theoretical research are presently being pursued, including secondgeneration detector design, data analysis, and numericalrelativity simulations of sources. This thesis presents a study in each of these topics: i) The noise in the most sensitive frequency bands in secondgeneration groundbased gravitationalwave interferometers is dominated by the thermal noise of the test masses. One way to reduce testmass thermal noise is to modify shape of the laser beam so that it better averages over the thermal fluctuations. When edge effects are neglected, the testmass thermal noise is related to the beam shape by simple scaling laws. This thesis presents a rigorous derivation of these laws, along with estimates of the errors made by neglecting edge effects. ii) An important class of gravitationalwave sources for spacebased gravitationalwave interferometers is extrememassratio inspirals (EMRIs). These are binaries in which an object of a few solar masses spirals into a (typically millionsolarmass) supermassive black hole (or, if any exist, other type of massive body). Ryan (1995) proved that, under certain simplifying assumptions, the spacetime geometry is redundantly encoded in EMRI waves. One of Ryan's assumptions was negligible tidal coupling. After first finding that only the timevarying part of the induced tide is unambiguously defined when the central body is a black hole, this thesis extends Ryan's theorem by showing that both the spacetime geometry and details of the tidal coupling are encoded in EMRI waves. iii) Merging black holes with comparable masses are important sources of gravitational waves for groundbased detectors. The gravitational waves near the time of merger can only be predicted by numerically solving the Einstein equations. Initial data in numerical simulations must contain the desired physical content but also satisfy the Einstein constraint equations. But conventional binaryblackhole initial data has physical flaws: a nonzero orbital eccentricity and an initial, unphysical pulse of spurious gravitational radiation. Using the CaltechCornell pseudospectral code, this thesis develops and implements methods to reduce both of these effects.
Item Type:  Thesis (Dissertation (Ph.D.)) 

Subject Keywords:  advanced LIGO; black holes; gravitational waves; initial data for binary black holes; numerical relativity; tidal coupling 
Degree Grantor:  California Institute of Technology 
Division:  Physics, Mathematics and Astronomy 
Major Option:  Physics 
Thesis Availability:  Public (worldwide access) 
Research Advisor(s): 

Thesis Committee: 

Defense Date:  14 May 2007 
Author Email:  geoffrey4444 (AT) gmail.com 
Record Number:  CaltechETD:etd05232007115433 
Persistent URL:  http://resolver.caltech.edu/CaltechETD:etd05232007115433 
Default Usage Policy:  No commercial reproduction, distribution, display or performance rights in this work are provided. 
ID Code:  1987 
Collection:  CaltechTHESIS 
Deposited By:  Imported from ETDdb 
Deposited On:  29 May 2007 
Last Modified:  26 Dec 2012 02:45 
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