Title Information
Title
Achieving a Detection of the 21 cm Signal of the Cosmic Dark Ages: Simulation and Forecasting of a Lunar Far Side Radio Array
Type of Resource (primo)
dissertations
Name: Personal
Name Part
Smith, Willow
Role
Role Term: Text
creator
Name: Personal
Name Part
Pober, Jonathan
Role
Role Term: Text
Advisor
Name: Personal
Name Part
Dell'Antonio, Ian
Role
Role Term: Text
Reader
Name: Personal
Name Part
Tucker, Greg
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Department of Physics
Role
Role Term: Text
sponsor
Origin Information
Copyright Date
2026
Physical Description
Extent
xiii, 88 p.
digitalOrigin
born digital
Note: thesis
Thesis (Ph. D.)--Brown University, 2026
Genre (aat)
theses
Abstract
We have yet to observe the universe between the Cosmic Microwave Background (CMB) at z~1100 and the first galaxies at z~14, a period known as the Cosmic Dark Ages, when the universe was largely neutral Hydrogen and Dark Matter interacting gravitationally. Despite the lack of luminous sources during the aptly named Dark Ages, there does exist an observable signal thanks to the quantum mechanical Hyperfine transition of neutral Hydrogen: the 21 cm line. It is well understood that observation of this signal has the potential to offer greater constraints than the CMB in the cosmic variance limit, a probe of inflationary perturbations, and a window into exotic physics models. However, the 21 cm signal is highly red-shifted to problematic frequencies (1-50 MHz) that have significant overlap with artificial sources of Radio Frequency Interference (RFI) and with regions of opacity in the Earth's ionosphere. As a result, radio experiments to observe the Dark Ages have set their sights on the far side of the Moon which shields from Earth-based RFI and lacks an ionosphere. Of course, constructing a radio telescope on the Moon is no easy picture, so it is paramount to forecast and simulate various instrument configurations before committing to an experiment. In this work, I present high-precision simulations of Lunar interferometric array concepts to examine two important hurdles: obtaining a high signal-to-noise ratio (SNR) in the presence of bright thermal noise and quantifying the extent of diffuse foreground contamination in 21 cm power spectrum measurements. Regarding the former, I present an update to the FarView configuration, as presented in Advances in Space Research, in order to achieve a 10 σ detection of the z=30 21 cm power spectrum with a ~100,000 dipole array in the absence of foregrounds. For the latter hurdle, I show that complex spectral structure arises from the coupling of one's instrument with the lunar regolith. Overall, I argue that these results necessitate that one be able to precisely model the electromagnetic response of one's antennas in order to measure the 21 cm power spectrum.
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/00880600")
Topic
Cosmology
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01087196")
Topic
Radio astronomy
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01087390")
Topic
Radio interferometers
Subject
Topic
21 cm cosmology
Subject
Topic
Lunar radio array
Language
Language Term (ISO639-2B)
English
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20260516