Isaak Markovich Khalatnikov (, ; 17 October 1919 – 9 January 2021) was a leading

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

theoretical physicist Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict natural phenomena. This is in contrast to experimental physics, which uses experi ...

who made significant contributions to many areas of

theoretical physics Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict List of natural phenomena, natural phenomena. This is in contrast to experimental p ...

, including

general relativity General relativity, also known as the general theory of relativity, and as Einstein's theory of gravity, is the differential geometry, geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of grav ...

quantum field theory In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines Field theory (physics), field theory and the principle of relativity with ideas behind quantum mechanics. QFT is used in particle physics to construct phy ...

, as well as the theory of quantum liquids. He is well known for his role in developing the Landau-Khalatnikov theory of

superfluidity Superfluidity is the characteristic property of a fluid with zero viscosity which therefore flows without any loss of kinetic energy. When stirred, a superfluid forms vortices that continue to rotate indefinitely. Superfluidity occurs in two ...

and the so-called BKL conjecture in the general theory of relativity.

Life and career

Isaak Khalatnikov was born into a

Ukrainian Jewish The history of the Jews in Ukraine dates back over a thousand years; Jewish communities have existed in the modern territory of Ukraine from the time of the Kievan Rus' (late 9th to mid-13th century). Important Jewish religious and cultural move ...

family in Yekaterinoslav (now

Dnipro Dnipro is Ukraine's fourth-largest city, with about one million inhabitants. It is located in the eastern part of Ukraine, southeast of the Ukrainian capital Kyiv on the Dnieper River, Dnipro River, from which it takes its name. Dnipro is t ...

Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...

) and graduated from Dnipropetrovsk State University with a degree in Physics in 1941. He had been a member of the Communist Party since 1944. He earned his doctorate in 1952. His wife Valentina was the daughter of Revolutionary hero

Mykola Shchors Mykola Oleksandrovych Shchors (; – 30 August 1919) was a member of the Communist Party of the Soviet Union, Russian Communist Party and a participant in the Russian Civil War, serving as Red Army commander. In 1918–1919 he fought against th ...

. Much of Khalatnikov's research was a collaboration with, or inspired by,

Lev Landau Lev Davidovich Landau (; 22 January 1908 – 1 April 1968) was a Soviet physicist who made fundamental contributions to many areas of theoretical physics. He was considered as one of the last scientists who were universally well-versed and ma ...

, including the ''Landau-Khalatnikov theory'' of

. During 1969 he briefly worked as a part-time professor of theoretical physics at

Leiden University Leiden University (abbreviated as ''LEI''; ) is a Public university, public research university in Leiden, Netherlands. Established in 1575 by William the Silent, William, Prince of Orange as a Protestantism, Protestant institution, it holds the d ...

. In 1970, inspired by the mixmaster model introduced by Charles W. Misner, then at

Princeton University Princeton University is a private university, private Ivy League research university in Princeton, New Jersey, United States. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial ...

, Khalatnikov, together with Vladimir Belinski and

Evgeny Lifshitz Evgeny Mikhailovich Lifshitz (; ; 21 February 1915 – 29 October 1985) was a leading Soviet physicist and brother of the physicist Ilya Lifshitz. Work Born into a Ukrainian Jewish family in Kharkov, Kharkov Governorate, Russian Empire (now K ...

, introduced what has become known as the BKL conjecture, which is widely regarded as one of the most outstanding open problems in the classical theory of

gravitation In physics, gravity (), also known as gravitation or a gravitational interaction, is a fundamental interaction, a mutual attraction between all massive particles. On Earth, gravity takes a slightly different meaning: the observed force b ...

. Khalatnikov directed the Landau Institute for Theoretical Physics in

Moscow Moscow is the Capital city, capital and List of cities and towns in Russia by population, largest city of Russia, standing on the Moskva (river), Moskva River in Central Russia. It has a population estimated at over 13 million residents with ...

from 1965 to 1992. He was elected to the

Academy of Sciences of the Soviet Union The Academy of Sciences of the Soviet Union was the highest scientific institution of the Soviet Union from 1925 to 1991. It united the country's leading scientists and was subordinated directly to the Council of Ministers of the Soviet Union (un ...

in 1984. He has been awarded the Landau Gold Medal, the

Humboldt Prize The Humboldt Research Award (), also known informally as the Humboldt Prize, is an award given by the Alexander von Humboldt Foundation of Germany to internationally renowned scientists and scholars who work outside of Germany in recognition of ...

, and the Marcel Grossmann Award. He was also a foreign member of the

Royal Society of London The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, r ...

. He was portrayed by actor Georg Nikoloff in the film '' The Theory of Everything''. Khalatnikov died in

Chernogolovka Chernogolovka () is a town in Moscow Oblast, Russia. Center of the town is located some 43 km (27 miles) northeast of the Moscow city limit and 59 km (37 miles) from Red Square. Its population in 2018 was 21,342. History Chernogolovk ...

on 9 January 2021, aged 101.Prominent Physicist Khalatnikov, Involved In Building 1st Soviet Nuclear Weapon, Dies
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Honours and awards

Order "For Merit to the Fatherland" The Order "For Merit to the Fatherland" () is a state decoration of the Russian Federation. It was instituted on 2 March 1994 by Presidential Decree 442. Until the re-establishment of the Order of St. Andrew in 1998, it was the highest order of ...

, 3rd class (1999) *

Order of Alexander Nevsky The Order of Alexander Nevsky () is an Order (distinction), order of merit of the Russia, Russian Federation named in honour of saint Alexander Nevsky (1220–1263) and bestowed to civil servants for twenty years or more of highly meritorious ser ...

(2020) *

Order of the October Revolution The Order of the October Revolution (, ''Orden Oktyabr'skoy Revolyutsii'') was instituted on 31 October 1967, in time for the 50th anniversary of the October Revolution. It was conferred upon individuals or groups for services furthering communis ...

(1986) *

Order of the Patriotic War The Order of the Patriotic War () is a Soviet Union, Soviet military Order (decoration), decoration that was awarded to all soldiers in the Soviet armed forces, security troops, and to Partisan (military), partisans for heroic deeds in the Easte ...

, 2nd class (1985) * Three Orders of the Red Banner of Labour (1954, 1956, 1975) *

Order of Friendship of Peoples The Order of Friendship of Peoples () was an order of the Soviet Union, and was awarded to persons (including non-citizens), organizations, enterprises, military units, as well as administrative subdivisions of the USSR for accomplishments in s ...

(1979) *

Order of the Badge of Honour The Order of the Badge of Honour () was a civilian award of the Soviet Union. It was established on 25 November 1935, and was conferred on citizens of the USSR for outstanding achievements in sports, production, scientific research and socia ...

(1950) * Stalin Prize, 2nd class (1953)
Marcel Grossmann Award
(2012) "For the discovery of a general solution of the Einstein equations with a cosmological singularity of an oscillatory chaotic character known as the BKL singularity" * Asteroid 468725 Khalat was named in his honor. The official was published by the

Minor Planet Center The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Funct ...

on 18 May 2019 ().

Partial bibliography

Books

* *

Selected academic works

* * * * * * * * * *

References

* * {{DEFAULTSORT:Khalatnikov, Isaak Markovich 1919 births 2021 deaths 20th-century Russian physicists 21st-century Russian physicists Scientists from Dnipro Communist Party of the Soviet Union members Foreign members of the Royal Society Full Members of the Russian Academy of Sciences Full Members of the USSR Academy of Sciences Academic staff of the Moscow Institute of Physics and Technology Oles Honchar Dnipro National University alumni Recipients of the Order "For Merit to the Fatherland", 3rd class Recipients of the Order of Alexander Nevsky Recipients of the Order of Friendship of Peoples Recipients of the Order of the Red Banner of Labour Recipients of the Stalin Prize Jewish Russian physicists Russian men centenarians Russian cosmologists 20th-century Russian memoirists Soviet cosmologists Soviet Jewish physicists Superfluidity Russian scientists Jewish centenarians Academic staff of Leiden University