Cosmology Research

A central focus of my work has been the development of the baryon acoustic oscillation method for the study of the cosmological distance scale and the evolution of dark energy.  My collaborators and I have studied the behavior of the acoustic peak in both linear perturbation theory and numerical simulations and the practical implementation of the method on real data.  I have been involved in many of the largest survey projects in astronomy, most notably the Sloan Digital Sky Survey and Dark Energy Spectroscopic Instrument.

In the past two decades, the acoustic peak method has become one of the mainstays of the study of dark energy.  In addition to SDSS and DESI, I have been involved with several different survey concepts, including ADEPT/JDEM/WFIRST and the Gemini/Subaru Wide-Field Multi-Object Spectrograph (which has now evolved into the Prime Focus Spectrograph concept).  

My group has been pushing to demonstrate the reliability of the acoustic peak method down to 0.1% in distance, the statistical limit of the most aggressive of these surveys.  We have developed large suites of cosmological simulations to pursue these tests.
 

The evolution of a point-like initial density perturbation from Eisenstein, Seo, and White (2007).  The graph shows the motion of the four cosmic components in spherical comoving coordinates.  The baryon-photon acoustic wave travels outward to reach a radius of 150 Mpc (500 million light-years) and then stalls, creating an excess in the clustering of galaxies that we can still detect today.  More information about this animation.
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