Saturday, October 17, 2020

Today (October 17, 1919) is the birthday of Isaac Markovich Kalatnikov, the physicist who discovered the common solution (B.K.L) with the cosmological integrity of Einstein's equations.

Today (October 17, 1919) is the birthday of Isaac Markovich Kalatnikov, the physicist who discovered the common solution (B.K.L) with the cosmological integrity of Einstein's equations. 

Isaac Markovich Khalatnikov was born on October 17, 1919, into a Jewish family in Dnipropetrovsk. He studied at the Dnipropetrovsk State University and graduated in 1941 with a degree in physics. Has been a member of the Soviet Commonwealth Party since 1944. He received his doctorate in 1952. His wife, Valentina, was the daughter of the revolutionary Nikolai Sukorsu. Most of his research, including Ilandov-Kalatnikov's theory of superconductivity, was carried out in conjunction with Ilandov or with the stimulus of later interest. 

Much of Khalatnikov's research has been a collaboration with, or inspired by, Lev Landau, including the Landau-Khalatnikov theory of superfluidity. In 1970, inspired by the mixmaster model introduced by Charles W. Misner, then at Princeton University, Khalatnikov, together with Vladimir A. Belinsky and Evgeny Mikhailovich 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. Khalatnikov directed the Landau Institute for Theoretical Physics in Moscow from 1965 to 1992. He was elected to the Soviet Academy of Sciences in 1984. He has been awarded the Landau Prize and the Alexander von Humboldt Award, and he is a foreign member of the Royal Society of London. He is portrayed by Georg Nikoloff in The Theory of Everything. 

A Belinski–Khalatnikov–Lifshitz (BKL) singularity is a model of the dynamic evolution of the Universe near the initial singularity, described by an anisotropic, chaotic solutions of the Einstein field equations of gravitation. According to this model, the Universe is chaotically oscillating around a gravitational singularity in which time and space become equal to zero. This singularity is physically real in the sense that it is a necessary property of the solution, and will appear also in the exact solution of those equations. The singularity is not artificially created by the assumptions and simplifications made by the other special solutions such as the Friedmann–Lemaître–Robertson–Walker, quasi-isotropic, and Kasner solutions.

                                    

The model is named after its authors Vladimir Belinski, Isaak Khalatnikov, and Evgeny Lifshitz, then working at the Landau Institute for Theoretical Physics. The picture developed by BKL has several important elements. These are:

                                 Y10.gif

Near the singularity the evolution of the geometry at different spatial points decouples so that the solutions of the partial differential equations can be approximated by solutions of ordinary differential equations with respect to time for appropriately defined spatial scale factors. This is called the BKL conjecture.

                                    Spherical Harmonics

For most types of matter the effect of the matter fields on the dynamics of the geometry becomes negligible near the singularity. Or, in the words of John Wheeler, "matter doesn't matter" near a singularity. The original BKL work posed a negligible effect for all matter but later they theorized that "stiff matter" (equation of state p = ε) equivalent to a massless scalar field can have a modifying effect on the dynamics near the singularity.

                                            Drawing spherical harmonic density plots on the surface of a sphere in  tikz/pgfplots - TeX - LaTeX Stack Exchange

The ordinary differential equations describing the asymptotics come from a class of spatially homogeneous solutions which constitute the Mixmaster dynamics: a complicated oscillatory and chaotic model that exhibits properties similar to those discussed by BKL. 

Isaac was filmed by Isaac Niccol in his 2014 film The Doctrine for All. He is best known for developing the BKL hypothesis in general relativity. He has received awards such as the Sudalin Prize (1953) and the Marshall Grossman Prize (2012) for his discovery of the general solution to the Einstein relativity equations with the cosmologically confusing oscilloscopic isolation point known as the BKL slippery point.

Source By: Wikipedia

Information: Ramesh, Assistant Professor of Physics, Nehru Memorial College, Puthanampatti.


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