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Hermann Nicolai
Hermann Nicolai (born 11 July 1952 in Friedberg) is a German theoretical physicist and director emeritus at the Max Planck Institute for Gravitational Physics in Potsdam-Golm. Education and career At Karlsruhe Institute of Technology, Hermann Nicolai, beginning in 1971, studied physics and mathematics with a ''Diplom'' in 1975 with a doctorate in 1978 under the supervision of Julius Wess. At Heidelberg University, Nicolai was from 1978 to 1979 an assistant in theoretical physics. From 1979 to 1986, he worked at CERN in Geneva as a staff member in the theory department. In 1983 he received his habilitation at Heidelberg University. He was a professor (with civil service grade C3) of theoretical physics at Karlsruhe Institute of Technology from 1986 to 1988 and from 1988 to 1997 a professor (with civil service grade C4) of theoretical physics at the University of Hamburg. At the Max Planck Institute for Gravitational Physics, Nicolai was head of the department "Quantum Gravity a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedberg, Hesse
Friedberg (; official name: ''Friedberg (Hessen)'') is a town and the capital of the Wetteraukreis district, in Hesse, Germany. In 1966, the town hosted the sixth '' Hessentag'' state festival, in 1979 the 19th. Geographical location Friedberg is located about north of Frankfurt am Main in the Wetterau region. The town is located on the river Usa, just before it flows into the Wetter (river). The town church in the center of the town is at a height of above sea level. To the west, the Friedberg area extends into the Taunus mountain range up to the high Steinkopf. Division of the town The town consists of 7 districts: * Bruchenbrücken * Friedberg * Dorheim * Ockstadt * Bauernheim * Fauerbach * Ossenheim History The old city was refounded by the Hohenstaufen dynasty of the Holy Roman Empire, conveniently located at important trading routes. The city initially rivaled Frankfurt am Main economically, with an important annual trading fair, and initial rapid expansion, thoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klung Wilhelmy Science Award
The Klung Wilhelmy Science Award is an annual German award in the field of science, alternating annually between the categories of chemistry and physics. It is bestowed upon outstanding younger German scientists under the age of 40. Previous award names *1973 to 2001 – Otto-Klung Award *2001 to 2007 – Otto-Klung-Weberbank Award *2007 to 2013 – Klung-Wilhelmy-Weberbank Award Selection process The prizewinners are selected by permanent committees at the Institutes of Chemistry and Biochemistry and the Department of Physics at the Freie Universität Berlin, Free University of Berlin, with additional input from professors at other universities. Proposals and nominations by nationally and internationally renowned scientists are also taken into consideration. Self-nominations will not be accepted. The final decision on the selection recommendations is made by the following foundations: the Otto-Klung-Stiftung, Otto Klung Foundation at the Freie Universität Berlin, Free Univ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamical Billiards
A dynamical billiard is a dynamical system in which a particle alternates between free motion (typically as a straight line) and specular reflections from a boundary. When the particle hits the boundary it reflects from it Elastic collision, without loss of speed (i.e. elastic collisions). Billiards are Hamiltonian mechanics, Hamiltonian idealizations of the billiards, game of billiards, but where the region contained by the boundary can have shapes other than rectangular and even be multidimensional. Dynamical billiards may also be studied on non-Euclidean geometry, non-Euclidean geometries; indeed, the first studies of billiards established their ergodic theory, ergodic motion on surface (mathematics), surfaces of constant negative curvature. The study of billiards which are kept out of a region, rather than being kept in a region, is known as outer billiard theory. The motion of the particle in the billiard is a straight line, with constant energy, between reflections with the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BKL Singularity
A Belinski–Khalatnikov–Lifshitz (BKL) singularity is a model of the dynamic evolution of the universe near the initial gravitational singularity, described by an anisotropic, chaotic solution of the Einstein field equation of gravitation. According to this model, the universe is chaotically oscillating around a gravitational singularity in which time and space become equal to zero or, equivalently, the spacetime curvature becomes infinitely big. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Big Bang
The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models based on the Big Bang concept explain a broad range of phenomena, including the abundance of light elements, the cosmic microwave background (CMB) radiation, and large-scale structure. The uniformity of the universe, known as the horizon and flatness problems, is explained through cosmic inflation: a phase of accelerated expansion during the earliest stages. A wide range of empirical evidence strongly favors the Big Bang event, which is now essentially universally accepted.: "At the same time that observations tipped the balance definitely in favor of the relativistic big-bang theory, ..." Detailed measurements of the expansion rate of the universe place the Big Bang singularity at an estimated billion years ago, which is considered the age of the universe. Extrapolating this cosmic expansion backward in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gravitational Singularity
A gravitational singularity, spacetime singularity, or simply singularity, is a theoretical condition in which gravity is predicted to be so intense that spacetime itself would break down catastrophically. As such, a singularity is by definition no longer part of the regular spacetime and cannot be determined by "where" or "when”. Gravitational singularities exist at a junction between general relativity and quantum mechanics; therefore, the properties of the singularity cannot be described without an established theory of quantum gravity. Trying to find a complete and precise definition of singularities in the theory of general relativity, the current best theory of gravity, remains a difficult problem. A singularity in general relativity can be defined by the scalar invariant curvature becoming infinite or, better, by a geodesic being incomplete. General relativity predicts that any object collapsing beyond its Schwarzschild radius would form a black hole, inside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin (physics)
Spin is an Intrinsic and extrinsic properties, intrinsic form of angular momentum carried by elementary particles, and thus by List of particles#Composite particles, composite particles such as hadrons, atomic nucleus, atomic nuclei, and atoms. Spin is quantized, and accurate models for the interaction with spin require relativistic quantum mechanics or quantum field theory. The existence of electron spin angular momentum is inferred from experiments, such as the Stern–Gerlach experiment, in which silver atoms were observed to possess two possible discrete angular momenta despite having no orbital angular momentum. The relativistic spin–statistics theorem connects electron spin quantization to the Pauli exclusion principle: observations of exclusion imply half-integer spin, and observations of half-integer spin imply exclusion. Spin is described mathematically as a vector for some particles such as photons, and as a spinor or bispinor for other particles such as electrons. Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graviton
In theories of quantum gravity, the graviton is the hypothetical elementary particle that mediates the force of gravitational interaction. There is no complete quantum field theory of gravitons due to an outstanding mathematical problem with renormalization in general relativity. In string theory, believed by some to be a consistent theory of quantum gravity, the graviton is a massless state of a fundamental string. If it exists, the graviton is expected to be massless because the gravitational force has a very long range and appears to propagate at the speed of light. The graviton must be a spin-2 boson because the source of gravitation is the stress–energy tensor, a second-order tensor (compared with electromagnetism's spin-1 photon, the source of which is the four-current, a first-order tensor). Additionally, it can be shown that any massless spin-2 field would give rise to a force indistinguishable from gravitation, because a massless spin-2 field would couple to the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supersymmetry
Supersymmetry is a Theory, theoretical framework in physics that suggests the existence of a symmetry between Particle physics, particles with integer Spin (physics), spin (''bosons'') and particles with half-integer spin (''fermions''). It proposes that for every known particle, there exists a partner particle with different spin properties. There have been multiple experiments on supersymmetry that have failed to provide evidence that it exists in nature. If evidence is found, supersymmetry could help explain certain phenomena, such as the nature of dark matter and the hierarchy problem in particle physics. A supersymmetric theory is a theory in which the equations for force and the equations for matter are identical. In theoretical physics, theoretical and mathematical physics, any theory with this property has the ''principle of supersymmetry'' (SUSY). Dozens of supersymmetric theories exist. In theory, supersymmetry is a type of Spacetime symmetries, spacetime symmetry betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eleven-dimensional Supergravity
In supersymmetry, eleven-dimensional supergravity is the theory of supergravity in the highest number of dimensions allowed for a supersymmetric theory. It contains a graviton, a gravitino, and a 3-form gauge field, with their interactions uniquely fixed by supersymmetry. Discovered in 1978 by Eugène Cremmer, Bernard Julia, and Joël Scherk, it quickly became a popular candidate for a theory of everything during the 1980s. However, interest in it soon faded due to numerous difficulties that arise when trying to construct physically realistic models. It came back to prominence in the mid-1990s when it was found to be the low energy limit of M-theory, making it crucial for understanding various aspects of string theory. History Supergravity was discovered in 1976 through the construction of pure four-dimensional supergravity with one gravitino. One important direction in the supergravity program was to try to construct four-dimensional \mathcal N = 8 supergravity since thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bernard De Wit
Bernard Quirinus Petrus Joseph de Wit (born 1945 in Bergen op Zoom) is a Dutch theoretical physicist specializing in supergravity and particle physics. Bernard de Wit studied theoretical physics at Utrecht University, where he got his PhD under supervision of Nobel Prize laureate Martinus Veltman in 1973. After postdoc stints in Stony Brook, Utrecht and Leiden, he became a staff member at National Institute for Nuclear and High Energy Physics ( NIKHEF) in 1978, where became head of the theory group in 1981. In 1984 he became professor of theoretical physics at Utrecht University where he has stayed for the rest of his career. During the years, de Wit spent several periods at CERN The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in Meyrin, western suburb of Gene ... as a visiting scientist in the Theory Division. He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Hannover
Leibniz University Hannover (), also known as the University of Hannover, is a public research university located in Hanover, Germany. Founded on 2 May 1831 as Higher Vocational School, the university has undergone six periods of renaming, its most recent in 2006. Leibniz University Hannover is a member of TU9, an association of the nine leading Institutes of Technology in Germany. It is also a member of the Conference of European Schools for Advanced Engineering Education and Research, a non-profit association of leading engineering universities in Europe. The university sponsors the German National Library of Science and Technology, the largest science and technology library in the world.Profile of the TIB at Leibniz University Hannoveonline (English) retrieved 26 May 2012 History The roots of the university begin in the Higher Vocational College/Polytechnic Institute (), founded on 2 May 1831. In 1879 the Higher Vocational School moved into the historic Guelph palace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
