Contact Information
Harvard-Smithsonian Center for Astrophysics
60 Garden St., MS 51
Cambridge, MA 02138
Office: P-223, Phone: (617) 384-9665, Fax: (617) 495-7093 mzaldarriaga@cfa.harvard.edu

Research Interests
Matias Zaldarriaga's research area is theoretical astrophysics with emphasis in cosmology. Observations of the universe on the largest scales are currently providing a wealth of information about the matter content of the universe and the dynamics of its constituents. Examples of such observations are measurements of the anisotropies in the Cosmic Microwave Background which provide a map of the universe as it was 400,000 years after the Big Bang, measures of fluctuations in the local density of galaxies and measures of fluctuations in the density of neutral hydrogen along the line of sight to distant sources.

Matias Zaldarriaga's has worked on making theoretical predictions for these various observational probes. He has worked on the polarization anisotropies of the Cosmic Microwave Background and shown how polarization can be used to detect a stochastic background of gravitational waves left over from the very early universe, and how polarization can discriminate between different scenarios of how hydrogen in the universe became ionized by the first generation of luminous objects. He has studied how secondary effects such as gravitational lensing alters the anisotropies in the CMB and worked on how different probes of density fluctuations can be used to inferred the scale dependence of the primordial seeds of structure formation.

Tegmark, M., and M. Zaldarriaga. "Separating the Early Universe from the Late Universe: Cosmological Parameter Estimation beyond the Black Box." Physical Review D 66, 103508 (2002).

Zaldarriaga, M. "Searching for Fluctuations in the Intergalactic Medium Temperature Using the Lyα Forest." Astrophysical Journal 564: 153-161 (2002).

Spergel, D. N., and M. Zaldarriaga. "Cosmic Microwave Background Polarization as a Direct Test of Inflation." Physical Review Letters 79: 2180-2183 (1997).

Seljak, U., and M. Zaldarriaga. "Signature of Gravity Waves in the Polarization of the Microwave Background." Physical Review Letters 78: 2054-2057 (1997).

Seljak, U., and M. Zaldarriaga. "A Line-of-Sight Integration Approach to Cosmic Microwave Background Anisotropies." Astrophysical Journal 469: 437 (1996).