In 1952, Zeldovich began work in the field of
elementary particles and their transformations. He predicted the
beta decay of a
pi meson. Together with
Semyon Gershtein he noticed the analogy between the
weak and
electromagnetic interactions, and in 1960, he predicted the
muon catalysis (more precisely, the muon-catalysed dt-fusion) phenomenon. In 1977, Zeldovich together with was awarded the
Kurchatov Medal, the highest award in nuclear physics of the Soviet Union. The citation was "for prediction of characteristics of
ultracold neutrons, their detection and investigation". He was elected academician of the USSR Academy of Sciences on 20 June 1958. He was a head of division at the
Institute of the Applied Mathematics of the USSR Academy of Sciences from 1965 until January 1983. in 1977 In early 1960s, Zeldovich started working in
astrophysics and
physical cosmology. In 1964, he and independently
Edwin Salpeter were the first to suggest that
accretion discs around massive
black holes are responsible for the huge amounts of energy radiated by
quasars. From 1965, he was a professor at the Department of Physics of the
Moscow State University and a head of the division of
Relativistic Astrophysics at the
Sternberg Astronomical Institute. In 1966, he and
Igor Novikov were the first to propose searching for black hole candidates among binary systems in which one star is optically bright and X-ray dark and the other optically dark but X-ray bright (the black hole candidate). Zeldovich worked on the theory of the evolution of the hot universe, the properties of the
microwave background radiation, the
large-scale structure of the universe, and the theory of
black holes. He predicted, with
Rashid Sunyaev, that the cosmic microwave background should undergo inverse
Compton scattering. This is called the
Sunyaev-Zeldovich effect, and measurements by telescopes such as the
Atacama Cosmology Telescope and the
South Pole Telescope has established it as one of the key observational probes of cluster cosmology. Zeldovich contributed sharp insights into the nature of the large scale structure of the universe, in particular, through the use of Lagrangian perturbation theory (the Zeldovich approximation) and the application of the Burgers' equation approach via the adhesion approximation. In 1974, in collaboration with A. G. Polnarev, suggested the existence of a
gravitational memory effect, for which a system of freely falling particles initially at relative rest are displaced after the passing of a burst of
gravitational radiation.
Black hole thermodynamics Zeldovich played a key role in developing the theory of
black hole evaporation due to
Hawking radiation. Zeldovich and
Charles W. Misner concomitantly predicted the possibility of particle generation by rotating
Kerr black holes in 1971, 1972. Previously, In 1965, Zeldovich had predicted that Kerr black holes would split the emission lines of photons as in a Zeeman effect. During
Stephen Hawking's visit to Moscow in 1973, Soviet scientists Zeldovich and
Alexei Starobinsky showed Hawking that, according to the quantum mechanical
uncertainty principle,
rotating black holes should create and emit particles. ==Family==