Ross Cawthon
Graduate Student, Department of Astronomy and Astrophysics

Location: ERC 448
CV | Webpage

Scientific Advisor: Joshua A. Frieman

Affiliations: Kavli Institute for Cosmological Physics

Cosmology, Dark Energy, Large-Scale Structure
Cerro Tololo Inter-American Observatory, Chile. Center is the Blanco Telescope, home of the Dark Energy Survey. (Photo: Reidar Hahn)
Publications: ADS | arXiv
Description of large-scale structure and dark energy for the public:

Scientific Projects

Ph.D. Thesis Defense (Astronomy)
Defense date: July 18, 2018
Ph.D. Thesis: "Effects of Redshift Uncertainty on Cross-Correlations of CMB Lensing and Galaxy Surveys"

Ph.D. Committee members: Josh Frieman (PhD advisor), Scott Dodelson, Steve Kent, Dan Hooper

Thesis Abstract: Wide-field galaxy imaging surveys, such as the Dark Energy Survey (DES), and cosmic microwave background experiments, such as the South Pole Telescope (SPT), have great synergy in studying the large-scale structure of the Universe. One of the most important combined measurements from these types of surveys is the cross-correlation of galaxy positions with locations of gravitational lensing of the CMB.

In this thesis, I go in depth in projecting future cosmological constraints of this measurement. The key element of my work that has not been studied previously is the effect of redshift uncertainties on these constraints. I will show that discounting this effect can greatly overestimate the precision of these measurements. I will also show how some of this loss of precision can be mitigated, going from 50 times larger uncertainties than the perfectly known redshifts case, to only 2-3 times larger. A secondary goal of my work is to show that these measurements can simultaneously constrain the redshift information of samples of galaxies. I will show that these constraints on redshift information can be competitive with typical methods of estimating photometric redshifts. I will discuss projections of both the current DES/SPT era, and the exciting future era (2020s) of the Large Synoptic Survey Telescope (LSST) and the CMB-Stage 4 experiment.

Department Committees
Past Department Committees:
  • Graduate Admissions: 2017 - 2018
  • Broader Horizons: 2016 - 2017 | 2015 - 2016
  • Graduate Committee: 2014 - 2015 | 2013 - 2014

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