Discovering the QCD axion with black holes and gravitational waves

Placeholder Show Content

Abstract/Contents

Abstract
Advanced LIGO is the first experiment to detect gravitational waves. Through su- perradiance of stellar black holes, it may also be the first experiment to discover the QCD axion with decay constant above the GUT scale. When an axion's Comp- ton wavelength is comparable to the size of a black hole, the axion binds to the black hole, forming a "gravitational atom." Through the superradiance process, the number of axions occupying the bound levels grows exponentially, extracting energy and angular momentum from the black hole. Axions transitioning between levels of the gravitational atom and axions annihilating to gravitons can produce observable gravitational wave signals. The signals are long-lasting, monochromatic, and can be distinguished from ordinary astrophysical sources. We estimate up to O(1) transition events at aLIGO for an axion between 10^−11 and 10^−10 eV and up to 10^4 annihila- tion events for an axion between 10^−13 and 10^−11 eV. In the event of a null search, aLIGO can constrain the axion mass for a range of rapidly spinning black hole formation rates. Axion annihilations are also promising for much lighter masses at future lower-frequency gravitational wave observatories; the rates have large uncertainties, dominated by supermassive black hole spin distributions. Our projections for aLIGO are robust against perturbations from the black hole environment and account for our updated exclusion on the QCD axion of 6 × 10^−13 eV < μa < 2 × 10^−11 eV suggested by stellar black hole spin measurements.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2016
Issuance monographic
Language English

Creators/Contributors

Associated with Huang, Xinlu
Associated with Stanford University, Department of Physics.
Primary advisor Dimopoulos, Savas, 1952-
Thesis advisor Dimopoulos, Savas, 1952-
Thesis advisor Graham, Peter (Peter Wickelgren)
Thesis advisor Kachru, Shamit, 1970-
Advisor Graham, Peter (Peter Wickelgren)
Advisor Kachru, Shamit, 1970-

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Xinlu Huang.
Note Submitted to the Department of Physics.
Thesis Thesis (Ph.D.)--Stanford University, 2016.
Location electronic resource

Access conditions

Copyright
© 2016 by Xinlu Huang
License
This work is licensed under a Creative Commons Attribution 3.0 Unported license (CC BY).

Also listed in

Loading usage metrics...