Standing in front of the Blanco Telescope dome while on shift for DES in Chile.    Giving a public lecture on the CMB.




Github: jessmuir


About me

[Website under construction: updates to come soon.]

I recently defended my PhD and so am wrapping up my time as a graduate student in the University of Michigan's Department of Physicswhere I work with Professor Dragan Huterer as part of the Michigan cosmology group.  I'm interested in using cosmological observations to better understand and constrain fundamental physics, and in studying how we can get as much information as possible out of those observations. I'm also interested in science outreach and in making STEM fields more accessible and welcoming to everyone.

A native Michigander, I grew up in a suburb of Detroit (Romeo) and received my undergraduate degree from Michigan State UniversityI spent two years at the University of Cambridge as a Marshall Scholar where I completed Part III of the Mathematical Tripos and spent a year working on research on modified gravity with Professor Anne-Christine Davis. After that, I started the PhD program at the University of Michigan. In the fall of 2018 I'll be moving to the Bay Area to work as a Porat Fellow at Stanford. 

My CV is here. Contact me for the most up-to-date version. 

Current & recent projects

  • Blinding for the DES analysis - The Dark Energy Survey (DES) is an ongoing project to map 1/8th of the sky, and to use the information gathered from that survey to place constraints on, among other things, dark energy properties. I am part of the team working to implement strategies to prevent experimenter bias from influencing the cosmological analysis. 
  • Growth-geometry split analysis of DES data - Many models of modified gravity can produce the same expansion history as $\Lambda$CDM, the standard cosmological model of a cosmological constant + cold dark matter + general relativity, but will differ in their predictions for structure growth. The idea of the grow-geometry split analysis is to separately constrain the LCDM parameters using probes of expansion and structure growth, and then to use the comparison of those constraints as a consistency test of LCDM. I'm currently implementing and testing a pipeline to run this kind of analysis on the Year-1 data for DES. I'm also generally interested in using galaxy survey data to test for modified gravity via phenomenological parameterizations of deviations from general relativity. 
  • CMB anomaly covariances - For the most part, data from the CMB have been found to be in remarkable agreement with the predictions of LCDM. However, there are a handful of features on very large angular scales which are statistically unlikely in LCDM, which have been the subject of much study. I'm working on a project with others in my research group to use ensembles of simulated skies to characterize the extent to which these various anomalies are independent. 
  • ISW signal reconstruction - The integrated Sachs-Wolfe (ISW) effect is a result of the fact that the energy of cosmic microwave background (CMB) photons gets modulated when pass through gravitational potential wells associated with large scale structure (LSS) on their way from the surface of last scattering to us. This energy modulation contributes to CMB temperature anisotropies at large angles. One can use theoretical cross correlations and maps of LSS tracers to try to reconstruct a map of the ISW signal. In two recent papers (here and here), I explored how different survey properties and systematics affecting the input galaxy maps impacted the accuracy of this kind of ISW signal reconstruction.
Though I can't really claim it as a project, I was lucky enough to be on observing shift during the tail end of the DES follow-up observations of the binary neutron star collision detected by LIGO in August (see telescope photo above). Data I took played a small role in these three papers.   


PhD Physics - University of Michigan, 2018.
MPhil in Astronomy - Gonville and Caius College, University of Cambridge, 2013.
MASt in Applied Mathematics (Part III) - Gonville and Caius College, University of Cambridge, 2012.
B.S. Physics & B.S. Astrophysics - Michigan State University, 2010.