David is a Postdoctoral Scholar at JPL in the Cosmology Group of the Science Division. Currently, his main topic of research is weak gravitational lensing. David has been active in various projects within the Sloan Digital Sky Survey including, large-scale structure, a search for strongly-lensed quasars, weak lensing and measurements of galaxy clusters.

David is now involved in planning future weak lensing missions such as the SNAP satellite and applying the method of weak lensing to the HST COSMOS survey for the purpose of constraining the properties of dark matter and dark energy.

• B.S. (highest honors) in Physics and Mathematics - University of Michigan (1997)
• Ph.D. in Physics - University of Chicago (2004)

1. Johnston, D. , Sheldon, E.S., et al. 2005 Cross-Correlation Lensing: Determining Galaxy and Cluster Mass Profiles from Statistical Weak Lensing Measurements astro-ph507467
2. Johnston, D. 2005 Measuring the Galaxy-Galaxy-Mass Three-point Correlation Function with Weak Gravitational Lensing astro-ph503282
3. Pindor, B. et al. 2006 SDSS J102111.02+491330.4: A Newly Discovered Gravitationally Lensed Quasar The Astronomical Journal, 131, 41.
4. Tegmark,M. et al. 2004 Cosmological parameters from SDSS and WMAP Physical Review D, vol. 69, Issue 10.
5. Sheldon,E.S., Johnston, D., et al. 2004 The Galaxy-Mass Correlation Function Measured from Weak Lensing in the Sloan Digital Sky Survey Astronomical Journal 127, 2544.
6. Johnston, D., Richards, G.T., Frieman, J.A., Keeton, C., Becker, R., et al. 2003 SDSS~J0903+5028: A New Gravitational Lens Astronomical Journal 126, 2281.
7. Scranton, R., Johnston, D. et al. 2002 Analysis of Systematic Effects and Statistical Uncertainties in Angular Clustering of Galaxies from Early SDSS Data Astrophysical Journal 579, 48.