Alexei Alexandrovich Starobinsky was born on 19 April 1948 in
Moscow, in the former
Soviet Union, to two radio physicists.[1][2] He went to a physics and technology high school where he graduated in 1966.[1] He attended
Moscow State University, earning an
MSc degree in physics in 1972.[3] In 1975, he obtained a
PhD in theoretical and mathematical physics from the
Landau Institute for Theoretical Physics of the
Russian Academy of Sciences under the supervision of
Yakov Zeldovich with a thesis titled Quantum Effects and the Amplification of Waves in Strong Gravitational Forces.[4][5]
Career
After finishing his doctorate, he remained at the Landau Institute working as a research scientist. In 1997, he became the institute's principal research scientist, a position he held until his death. From 1990 to 1997, he headed the institute's department of gravitation and cosmology and, from 1999 to 2003, he was also the institute's deputy director.[2][6]
Starobinsky was a visiting professor at the
École Normale Supérieure in 1991, the Research Center for the Early Universe at the
University of Tokyo from 2000 to 2001, the
Institut Henri Poincaré in 2006, the Yukawa Institute for Theoretical Physics of
Kyoto University in 1994 and 2007, and
Utrecht University from 2014 to 2015.[6][7] In 2017, he was also appointed as a part-time professor at the National Research University Higher School of Economics[4]
Starobinsky's research commenced while he was still a student in the early 1970s with the study of particle creation in the early universe alongisde Zeldovich. In 1973, building on Zeldovich's prior research, he showed that, according to the
uncertainty principle, rotating black holes must emit particles.[10][11] They were visited in Moscow by
Stephen Hawking, who was spurred to find a precise mathematical treatment for this phenomenon.[12] He would later conjecture that all black holes (not just rotating ones) emit energetic particles, a theoretical effect known today as
Hawking radiation.[a][13][14]
Subsequently, Starobinsky shifted his focus to cosmology. He began investigating the early universe and the
Big Bang, attempting to use quantum mechanics and general relativity to understand how an expanding universe may have formed. In 1979, he was the first to propose a model for how the early universe could have gone through an extremely rapid period of exponential expansion.[15][16] His model, now known as
Starobinsky inflation,[b] postulates that the expansion was driven by
quantum gravity effects.[16] Starobinsky also found that this expansion would have produced
gravitational waves detectable today as a
background.[17] Despite its significance, his work remained unknown outside of the Soviet Union.[16][18] Around the same period,
Alan Guth independently proposed a theory of exponential expansion, which he termed '
inflation', to tackle the
horizon,
flatness and
magnetic monopole problems with the Big Bang.[15][19] The shortcomings with Guth's theory were successfully fixed by
Andrei Linde in 1981.[20]
The Starobinsky model of inflation implied that
quantum fluctuations, random disturbances of a point in space, would have been stretched beyond the quantum scale by the exponential expansion of the universe.[21]Viatcheslav Mukhanov and
Gennady Chibisov proposed that these quantum fluctuations eventually resulted in the largest structures in the universe.[22] Their predictions have been matched by observations of the cosmic microwave background.[19]
Personal life and politics
Starobinsky's father died when he was two years old.[1] In February 2022, he signed an open letter by Russian scientists condemning the
Russian invasion of Ukraine.[23][24] Starobinsky died on 21 December 2023 at the age of 75.[5] He is buried in the
Novodevichy cemetery.[25]
Starobinsky was awarded the 1996
Friedmann Prize for his work on the inflationary stage of the universe and its observational manifestations.[26]
In 2009, Starobinsky and Mukhanov were jointly awarded the
Tomalla Prize for their contributions to cosmological inflation. Starobinsky was specifically recognised for his calculations of the gravitational radiation emitted during the inflationary epoch of the universe.[27] He received the
Oskar Klein Medal in 2010.[2][28] Starobinsky and Mukhanov were also co-recipients of the Amaldi Medal from the
Italian Society for General Relativity and Gravitation in 2012 and the
Gruber Prize in Cosmology in 2013.[29][30]
^Hawking radiation has not yet been directly observed or proven experimentally. It is predicted to be incredibly faint and below the detecting ability of the current best telescopes.
^At the time, because the term 'inflation' had not yet been coined, the model was known just as the Starobinsky model.[16]
^
abc""У Алексея Старобинского была жажда высшей истины"" [Aleksej Starobinskij Had a Desire for Higher Truth]. St Philaret's Institute Свято-Филаретовский институт (in Russian). 21 December 2023.
Archived from the original on 14 January 2024. Retrieved 21 December 2023.
^"Press release". XV International Conference on Gravitation, Astrophysics and Cosmology (ICGAC15). 3 July 2023. Archived from
the original on 23 December 2023. Retrieved 23 December 2023.