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Fundamental Physics in the Era of Gravitational-Wave Astronomy: The Direct Measurement of Gravitational-Wave Polarizations and Other Topics


Isi Bañales, Maximiliano (2019) Fundamental Physics in the Era of Gravitational-Wave Astronomy: The Direct Measurement of Gravitational-Wave Polarizations and Other Topics. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/S15R-3495.


In this thesis, I explore several avenues for learning about fundamental physics from gravitational-wave (GW) observations. In particular, I focus on the phenomenological study of basic properties of GWs in ways that require minimal assumptions about the underlying nature of gravity. I place a special emphasis on GW polarizations, but also consider their speed and possible dispersion. To constrain possible modifications to general relativity, I develop data-analysis frameworks to measure these properties with both transient and persistent signals detected by ground-based detectors. This includes, among other results, the analysis of two LIGO and Virgo compact-binary detections, GW170814 and GW170817, to produce the first direct observational statements about the local geometry of GW polarizations. I also present constraints on the potential amplitude of nontensorial monochromatic signals from 200 known pulsars in the Milky Way and describe in detail the methods used to obtain them. Because stochastic signals will be a great resource for studying GW properties, I also carefully review the assumptions that go into standard stochastic analyses and explore their applicability beyond general relativity, concluding that those measurements will have to be interpreted carefully to make meaningful statements about corrections to Einstein’s theory. Besides the properties of the waves themselves, I also study the prospect for using GWs as a means to uncover signatures of new ultralight bosons—an exciting possibility that could bring particle physics into the reach of GW astronomy. I explore the potential of current and future detectors to detect these conjectured particles, concluding that third-generation instruments are certain to place theoretically interesting constraints. Because little can be done in the absence of signals, I also propose data-analysis methods to improve LIGO and Virgo’s chances of detecting both transient and continuous signals. The latter have now been used to diagnose real detection candidates on several occasions.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Gravitational waves; gravity; general relativity; ligo; polarizations; experimental tests of gravity
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Awards:Everhart Distinguished Graduate Student Lecturer Award, 2018.
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Weinstein, Alan Jay
Thesis Committee:
  • Chen, Yanbei (chair)
  • Weinstein, Alan Jay
  • Patterson, Ryan B.
  • Hopkins, Philip F.
Defense Date:5 October 2018
Funding AgencyGrant Number
Record Number:CaltechTHESIS:11042018-161928279
Persistent URL:
Related URLs:
URLURL TypeDescription 3 5 for Chapter 6 for Chapter 6 7 8 9 10
Isi Bañales, Maximiliano0000-0001-8830-8672
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11264
Deposited By: Maximiliano Isi Banales
Deposited On:20 Nov 2018 17:08
Last Modified:26 Oct 2021 18:04

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