Rainer K. Sachs

Rainer K. Sachs (Rainer Kurt "Ray" Sachs; born June 13, 1932) is a German-American computational radiation biologist and astronomer. He and Arthur M. Wolfe were the authors of the Sachs-Wolfe effect, which concerns a property of the Cosmic microwave background radiation. He and Ronald Kantowski were responsible for the Kantowski-Sachs dust solutions to the Einstein field equation. These are a widely used family of inhomogeneous cosmological models.

He was born in Frankfurt am Main in 1932, a son of the German Jewish metallurgist George Sachs. In 1937 the family left Germany to flee from Nazi persecution, and settled in the United States, so Rainer Sachs is generally considered an American scientist. He received his bachelor's degree in mathematics from MIT and his PhD in theoretical physics from Syracuse University.

From 1969 to 1993, he was Professor of Math and Physics at the University of California, Berkeley (UCB), and from 1993 he has been Professor Emeritus at UCB. In 1994, he was appointed Research Professor of Mathematics UCB, and since 2005 he has been an Adjunct Professor at the Tufts medical school.

Until 1985, he worked on general relativistic cosmology and astrophysics. With Hung-Hsi Wu he co-wrote the books General Relativity for Mathematicians and General Relativity and Cosmology. His contributions include joint work on the Sachs-Wolfe effect and the Ehlers-Geren-Sachs theorem, both of which deal with the Cosmic Microwave Background Radiation.

From 1985, he has worked in mathematical and computational biology, especially radiation biology. His work in radiobiology has included research on radiation and cancer.