Isaak Khalatnikov

Khalatnikov died in Chernogolovka on 9 January 2021, aged 101.

In 1970, inspired by the mixmaster model introduced by Charles W. Misner, then at Princeton University, Khalatnikov, together with Vladimir Belinski and Evgeny Lifshitz, 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.

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

Khalatnikov directed the Landau Institute for Theoretical Physics in Moscow from 1965 to 1992. He was elected to the Academy of Sciences of the Soviet Union in 1984. He has been awarded the Landau Gold Medal, the Humboldt Prize, and the Marcel Grossmann Award. He was also a foreign member of the Royal Society of London.

Isaak Khalatnikov was born into a Ukrainian Jewish family in Yekaterinoslav (now Dnipro, Ukraine) 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 Nikolay Shchors.

Isaak Markovych Khalatnykov ForMemRS (Ukrainian: Ісаа́к Ма́ркович Хала́тников; 17 October 1919 – 9 January 2021) was a leading Soviet theoretical physicist who has made significant contributions to many areas of theoretical physics, including general relativity, quantum field theory, as well as the theory of quantum liquids. He is well known for his role in developing the Landau-Khalatnikov theory of superfluidity and the so-called BKL conjecture in the general theory of relativity.