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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 made seminal contributions to all branches of physics. He is credited with laying the foundations of twentieth century condensed matter physics, and is also considered arguably the greatest Soviet theoretical physicist. His accomplishments include the independent co-discovery of the density matrix method in quantum mechanics (alongside John von Neumann), the quantum mechanical theory of diamagnetism, the theory of superfluidity, the theory of second-order phase transitions, invention of order parameter technique, the Ginzburg–Landau theory of superconductivity, the theory of Fermi liquids, the explanation of Landau damping in plasma physics, the Landau pole in quantum electrodynamics, the two-component theory of neutrinos, and Landau's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baku
Baku (, ; ) is the Capital city, capital and List of cities in Azerbaijan, largest city of Azerbaijan, as well as the largest city on the Caspian Sea and in the Caucasus region. Baku is below sea level, which makes it the List of capital cities by elevation, lowest lying national capital in the world and also the largest city in the world below sea level. Baku lies on the southern shore of the Absheron Peninsula, on the Bay of Baku. Baku's urban population was estimated at two million people as of 2009. Baku is the primate city of Azerbaijan—it is the sole metropolis in the country, and about 25% of all inhabitants of the country live in Baku's metropolitan area. Baku is divided into #Administrative divisions, twelve administrative raions and 48 townships. Among these are the townships on the islands of the Baku Archipelago, as well as the industrial settlement of Neft Daşları built on oil rigs away from Baku city in the Caspian Sea. The Old City (Baku), Old City, conta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niels Bohr
Niels Henrik David Bohr (, ; ; 7 October 1885 – 18 November 1962) was a Danish theoretical physicist who made foundational contributions to understanding atomic structure and old quantum theory, quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was also a philosopher and a promoter of scientific research. Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. Although the Bohr model has been supplanted by other models, its underlying principles remain valid. He conceived the principle of Complementarity (physics), complementarity: that items could be separately analysed in terms of contradictory properties, like behaving as a Wave–particle duality, wave or a stream of particles. The notion of complementarity dominated Bohr's thinking in both science and philoso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landau Free Energy
The grand potential or Landau potential or Landau free energy is a quantity used in statistical mechanics, especially for irreversible processes in open systems. The grand potential is the characteristic state function for the grand canonical ensemble. Definition The grand potential is defined by \Phi_\text \stackrel U - T S - \mu N where ''U'' is the internal energy, ''T'' is the temperature of the system, ''S'' is the entropy, ''μ'' is the chemical potential, and ''N'' is the number of particles in the system. The change in the grand potential is given by \begin d\Phi_\text & = dU - T\,dS - S\,dT - \mu d\,N - N\,d\mu \\ & = - P\,dV - S\,dT - N\,d\mu \end where ''P'' is pressure and ''V'' is volume, using the fundamental thermodynamic relation (combined first and second thermodynamic laws); dU = T\,dS - P\,dV + \mu\,dN When the system is in thermodynamic equilibrium, ΦG is a minimum. This can be seen by considering that ''d''ΦG is zero if the volume is fixed and the tem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamagnetism
Diamagnetism is the property of materials that are repelled by a magnetic field; an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagnetic materials are attracted by a magnetic field. Diamagnetism is a quantum mechanical effect that occurs in all materials; when it is the only contribution to the magnetism, the material is called diamagnetic. In paramagnetic and ferromagnetic substances, the weak diamagnetic force is overcome by the attractive force of magnetic dipoles in the material. The Permeability (electromagnetism), magnetic permeability of diamagnetic materials is less than the Vacuum_permeability, permeability of vacuum, ''μ''0. In most materials, diamagnetism is a weak effect which can be detected only by sensitive laboratory instruments, but a superconductivity, superconductor acts as a strong diamagnet because it entirely expels any magnetic field from its inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landau Pole
In physics, the Landau pole (or the Moscow zero, or the Landau ghost) is the momentum (or energy) scale at which the coupling constant (interaction strength) of a quantum field theory becomes infinite. Such a possibility was pointed out by the physicist Lev Landau and his colleagues in 1954. The fact that couplings depend on the momentum (or length) scale is the central idea behind the renormalization group. Landau poles appear in theories that are not asymptotically free, such as quantum electrodynamics (QED) or theory—a scalar field with a quartic interaction—such as may describe the Higgs boson. In these theories, the renormalized coupling constant grows with energy. A Landau pole appears when the coupling becomes infinite at a finite energy scale. In a theory purporting to be complete, this could be considered a mathematical inconsistency. A possible solution is that the renormalized charge could go to zero as the cut-off is removed, meaning that the charge is complete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landau Gauge
In the physics of gauge theories, gauge fixing (also called choosing a gauge) denotes a mathematical procedure for coping with redundant degrees of freedom in field variables. By definition, a gauge theory represents each physically distinct configuration of the system as an equivalence class of detailed local field configurations. Any two detailed configurations in the same equivalence class are related by a certain transformation, equivalent to a shear along unphysical axes in configuration space. Most of the quantitative physical predictions of a gauge theory can only be obtained under a coherent prescription for suppressing or ignoring these unphysical degrees of freedom. Although the unphysical axes in the space of detailed configurations are a fundamental property of the physical model, there is no special set of directions "perpendicular" to them. Hence there is an enormous amount of freedom involved in taking a "cross section" representing each physical configuration ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landau Distribution
Landau (), officially Landau in der Pfalz (, ), is an autonomous (''kreisfrei'') town surrounded by the Südliche Weinstraße ("Southern Wine Route") district of southern Rhineland-Palatinate, Germany. It is a university town (since 1990), a long-standing cultural centre, and a market and shopping town, surrounded by vineyards and wine-growing villages of the Palatinate wine region. Landau lies east of the Palatinate forest, on the German Wine Route. It contains the districts (''Ortsteile'') of Arzheim, Dammheim, Godramstein, Mörlheim, Mörzheim, Nussdorf, Queichheim, and Wollmesheim. History and other settings Landau was first mentioned as a settlement in 1106. It was in the possession of the counts of Leiningen-Dagsburg-Landeck, whose arms, differenced by an escutcheon of the Imperial eagle, served as the arms of Landau until 1955. The town was granted a charter in 1274 by King Rudolf I of Germany, who declared the town a Free Imperial Town in 1291; nevertheless Prince-B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landau Damping
In physics, Landau damping, named after its discoverer,Landau, L. "On the vibration of the electronic plasma". ''JETP'' 16 (1946), 574. English translation in ''J. Phys. (USSR)'' 10 (1946), 25. Reproduced in Collected papers of L.D. Landau, edited and with an introduction by D. ter Haar, Pergamon Press, 1965, pp. 445–460; and in Men of Physics: L.D. Landau, Vol. 2, Pergamon Press, D. ter Haar, ed. (1965). Soviet Union, Soviet physicist Lev Landau, Lev Davidovich Landau (1908–68), is the effect of Damping ratio, damping (exponential decay, exponential decrease as a function of time) of plasma oscillation, longitudinal space charge waves in Plasma (physics), plasma or a similar environment.Chen, Francis F. ''Introduction to Plasma Physics and Controlled Fusion''. Second Ed., 1984 Plenum Press, New York. This phenomenon prevents an instability from developing, and creates a region of stability in the parameter space. It was later argued by Donald Lynden-Bell that a similar phenomeno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Kharkiv, Ukraine). Lifshitz is well known in the field of general relativity for coauthoring the BKL conjecture concerning the nature of a ''generic curvature singularity''. , this is widely regarded as one of the most important open problems in the subject of classical gravitation. With Lev Landau, Lifshitz co-authored '' Course of Theoretical Physics'', an ambitious series of physics textbooks, in which the two aimed to provide a graduate-level introduction to the entire field of physics. These books are still considered invaluable and continue to be widely used. Lifshitz was the second of only 43 people ever to pass Landau's "Theoretical Minimum" examination. He made many invaluable contributions, in particular to quantum electrodynami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lev Pitaevskii
Lev Petrovich Pitaevskii ( ; 18 January 1933 – 23 August 2022) was a Russian theoretical physicist, who made contributions to the theory of quantum mechanics, electrodynamics, low-temperature physics, plasma physics, and condensed matter physics. Together with his PhD supervisor Evgeny Lifshitz and with Vladimir Berestetskii, he was also the co-author of a few volumes of the influential Landau–Lifschitz '' Course of Theoretical Physics'' series. His academic status was professor. Education Pitaevskii was born in Saratov on 18 January 1933. He graduated from Saratov State University in 1955. In 1958, he joined the staff of the Institute of Physical Problems of the Russian Academy of Sciences. In 1971, he became a professor at the Moscow Institute of Physics and Technology. Research Collaborating with Vitaly Ginzburg, Pitaevskii developed a theory of superfluidity in the neighbourhood of a transition point. He showed that, at sufficiently low temperatures, liquid helium-3 sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
