Matias Zaldarriaga is an Argentine cosmologist.
Born in Coghlan neighbourhood, Buenos Aires, at the present time he works in the Institute for Advanced Study located in Princeton, New Jersey, United States. He is known especially for his work on the cosmic microwave background (CMB). Together with Uros Seljak, he developed the CMBFAST code, the first computationally efficient method for computing the anisotropy of the CMB for an arbitrary set of cosmological parameters.
In 2003, he was awarded the Helen B. Warner Prize for Astronomy by the American Astronomical Society, and in 2005 he won the Gribov Medal of the European Physical Society. In
2006, he was the recipient of a MacArthur Fellowship.