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Jean Ginibre
Jean Ginibre (4 March 1938 — 26 March 2020) was a French mathematical physicist. He is known for his contributions to random matrix theory (see circular law), statistical mechanics (see FKG inequality, Ginibre inequality), and partial differential equations. With Martine Le Berre and Yves Pomeau, he provided a kinetic theory for the emission of photons by an atom maintained in an excited state by an intense field that creates Rabi oscillations. He received the Paul Langevin Prize in 1969. Jean Ginibre was Emeritus Professor at Paris-Sud 11 University Paris-Sud University (French: ''Université Paris-Sud''), also known as University of Paris — XI (or as Université d'Orsay before 1971), was a French research university distributed among several campuses in the southern suburbs of Paris, in .... He directed the thesis of Monique Combescure. See also * Classical XY model References 1938 births 2020 deaths French mathematicians French physicists Mathematical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circular Law
In probability theory, more specifically the study of random matrices, the circular law concerns the distribution of eigenvalues of an random matrix with independent and identically distributed entries in the limit . It asserts that for any sequence of random matrices whose entries are independent and identically distributed random variables, all with mean zero and variance equal to , the limiting spectral distribution is the uniform distribution over the unit disc. Precise statement Let (X_n)_^\infty be a sequence of matrix ensembles whose entries are i.i.d. copies of a complex random variable with mean 0 and variance 1. Let \lambda_1, \ldots, \lambda_n, 1 \leq j \leq n denote the eigenvalues of \displaystyle \fracX_n . Define the empirical spectral measure of \displaystyle \frac X_n as : \mu_(A) = n^ \#\~, \quad A \in \mathcal(\mathbb). With these definitions in mind, the circular law asserts that almost surely (i.e. with probability one), the sequence of meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Differential Equations
In mathematics, a partial differential equation (PDE) is an equation which imposes relations between the various partial derivatives of a multivariable function. The function is often thought of as an "unknown" to be solved for, similarly to how is thought of as an unknown number to be solved for in an algebraic equation like . However, it is usually impossible to write down explicit formulas for solutions of partial differential equations. There is, correspondingly, a vast amount of modern mathematical and scientific research on methods to numerically approximate solutions of certain partial differential equations using computers. Partial differential equations also occupy a large sector of pure mathematical research, in which the usual questions are, broadly speaking, on the identification of general qualitative features of solutions of various partial differential equations, such as existence, uniqueness, regularity, and stability. Among the many open questions are the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2020 Deaths
This is a list of deaths of notable people, organised by year. New deaths articles are added to their respective month (e.g., Deaths in ) and then linked here. 2022 2021 2020 2019 2018 2017 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 See also * Lists of deaths by day The following pages, corresponding to the Gregorian calendar, list the historical events, births, deaths, and holidays and observances of the specified day of the year: Footnotes See also * Leap year * List of calendars * List of non-standard ... * Deaths by year {{DEFAULTSORT:deaths by year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1938 Births
Events January * January 1 ** The Constitution of Estonia#Third Constitution (de facto 1938–1940, de jure 1938–1992), new constitution of Estonia enters into force, which many consider to be the ending of the Era of Silence and the authoritarian regime. ** state-owned enterprise, State-owned railway networks are created by merger, in France (SNCF) and the Netherlands (Nederlandse Spoorwegen – NS). * January 20 – King Farouk of Egypt marries Safinaz Zulficar, who becomes Farida of Egypt, Queen Farida, in Cairo. * January 27 – The Honeymoon Bridge (Niagara Falls), Honeymoon Bridge at Niagara Falls, New York, collapses as a result of an ice jam. February * February 4 ** Adolf Hitler abolishes the War Ministry and creates the Oberkommando der Wehrmacht (High Command of the Armed Forces), giving him direct control of the German military. In addition, he dismisses political and military leaders considered unsympathetic to his philosophy or policies. Gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical XY Model
The classical XY model (sometimes also called classical rotor (rotator) model or O(2) model) is a lattice model of statistical mechanics. In general, the XY model can be seen as a specialization of Stanley's ''n''-vector model for . Definition Given a -dimensional lattice , per each lattice site there is a two-dimensional, unit-length vector The ''spin configuration'', is an assignment of the angle for each . Given a ''translation-invariant'' interaction and a point dependent external field \mathbf_=(h_j,0), the ''configuration energy'' is : H(\mathbf) = - \sum_ J_\; \mathbf_i\cdot\mathbf_j -\sum_j \mathbf_j\cdot \mathbf_j =- \sum_ J_\; \cos(\theta_i-\theta_j) -\sum_j h_j\cos\theta_j The case in which except for nearest neighbor is called ''nearest neighbor'' case. The ''configuration probability'' is given by the Boltzmann distribution with inverse temperature : :P(\mathbf)=\frac \qquad Z=\int_ \prod_ d\theta_j\;e^. where is the normalization, or partition fun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monique Combescure
Monique Combescure (born 23 April 1950, née Moulin), is a French physicist specializing in mathematical physics. In 2001, she became director of research at the Lyon Institute of Nuclear Physics. From 2000 to 2008, she was director of the European Mathematics and Quantum Physics Research Group (GDRE MPhiQ) which aims to promote synergy between Theoretical physics, theoretical physicists and mathematicians in the field of Quantum mechanics, quantum physics. She received the Irène-Joliot-Curie Prize in 2007 and the rank of Officer of the National Order of Merit in 2011. Life and work In 1970, Combescure joined the École Normale Supérieure in Paris and decided to devote herself to research in theoretical physics. She defended her thesis at the Paris-Sud University, University of Paris-Sud in 1974 on the problem of 3-body quantum scattering under the supervision of Jean Ginibre. She was then assigned to the theoretical and Particle physics, high-energy physics laboratory at Orsay ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paris-Sud 11 University
Paris-Sud University (French: ''Université Paris-Sud''), also known as University of Paris — XI (or as Université d'Orsay before 1971), was a French research university distributed among several campuses in the southern suburbs of Paris, including Orsay, Cachan, Châtenay-Malabry, Sceaux, and Kremlin-Bicêtre campuses. The main campus was located in Orsay. Starting from 2020, University Paris Sud has been replaced by the University of Paris-Saclay in The League of European Research Universities (LERU). Paris-Sud was one of the largest and most prestigious universities in France, particularly in science and mathematics. The university was ranked 1st in France, 9th in Europe and 37th worldwide by 2019 Academic Ranking of World Universities (ARWU) in particular it was ranked as 1st in Europe for physics and 2nd in Europe for mathematics. Five Fields Medalists and two Nobel Prize Winners have been affiliated to the university. On 16 January 2019, Alain Sarfati was elected P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Langevin Prize
The ''prix Paul-Langevin'' is a prize created in 1956 and named in honor of Paul Langevin. It has been awarded each year since 1957 by the ''Société française de physique'' (SFP). The prize honors French physicists for work in theoretical physics. The ''prix Paul Langevin'' should not be confused with the ', which is a prize awarded in mathematics, physics, chemistry, or biology by the French Academy of Sciences, ''Académie des sciences''. Recipients * 1957 Yves Ayant * 1958 Jacques Winter * 1959 Roland Omnès * 1960 Philippe Nozières * 1961 Cyrano de Dominicis * 1962 Jacques Villain * 1963 Claude Cohen-Tannoudji * 1964 Marcel Froissart * 1965 Robert Arvieu * 1966 Roger Balian * 1967 Jean Lascoux * 1968 Émile Daniel * 1969 Jean Ginibre * 1970 Daniel Bessis * 1971 Loup Verlet * 1972 Claude Itzykson * 1973 André Neveu * 1974 Édouard Brézin * 1975 Dominique Vautherin * 1976 Gérard Toulouse * 1977 Jean Zinn-Justin * 1978 Jean Iliopoulos * 1979 Richard Schaeffer * 1980 Roland ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yves Pomeau
Yves Pomeau, born in 1942, is a French mathematician and physicist, emeritus research director at the CNRS and corresponding member of the French Academy of sciences. He was one of the founders of thLaboratoire de Physique Statistique, École Normale Supérieure, Paris He is the son of René Pomeau. Career Yves Pomeau did his state thesis in plasma physics, almost without any adviser, at the University of Orsay-France in 1970. After his thesis, he spent a year as a postdoc with Ilya Prigogine in Brussels. He was a researcher at the CNRS from 1965 to 2006, ending his career as DR0 in the Physics Department of the Ecole Normale Supérieure (ENS) (Statistical Physics Laboratory) in 2006. He was a lecturer in physics at the École Polytechnique for two years (1982–1984), then a scientific expert with the Direction générale de l'armement until January 2007. He was Professor, with tenure, part-time at the Department of Mathematics, University of Arizona, from 1990 to 2008. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ginibre Inequality
In statistical mechanics, the Griffiths inequality, sometimes also called Griffiths–Kelly–Sherman inequality or GKS inequality, named after Robert B. Griffiths, is a correlation inequality for ferromagnetic spin systems. Informally, it says that in ferromagnetic spin systems, if the 'a-priori distribution' of the spin is invariant under spin flipping, the correlation of any monomial of the spins is non-negative; and the two point correlation of two monomial of the spins is non-negative. The inequality was proved by Griffiths for Ising ferromagnets with two-body interactions, then generalised by Kelly and Sherman to interactions involving an arbitrary number of spins, and then by Griffiths to systems with arbitrary spins. A more general formulation was given by Ginibre, and is now called the Ginibre inequality. Definitions Let \textstyle \sigma=\_ be a configuration of (continuous or discrete) spins on a lattice ''Λ''. If ''A'' ⊂ ''Λ'' is a list of lattice sites, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FKG Inequality
In mathematics, the Fortuin–Kasteleyn–Ginibre (FKG) inequality is a correlation inequality, a fundamental tool in statistical mechanics and probabilistic combinatorics (especially random graphs and the probabilistic method), due to . Informally, it says that in many random systems, increasing events are positively correlated, while an increasing and a decreasing event are negatively correlated. It was obtained by studying the random cluster model. An earlier version, for the special case of i.i.d. variables, called Harris inequality, is due to , see below. One generalization of the FKG inequality is the Holley inequality (1974) below, and an even further generalization is the Ahlswede–Daykin "four functions" theorem (1978). Furthermore, it has the same conclusion as the Griffiths inequalities, but the hypotheses are different. The inequality Let X be a finite distributive lattice, and ''μ'' a nonnegative function on it, that is assumed to satisfy the (FKG) lattice condit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
