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Stanley Mandelstam
Stanley Mandelstam (; 12 December 1928 – 23 June 2016) was a South African theoretical physicist. He introduced the relativistically invariant Mandelstam variables into particle physics in 1958 as a convenient coordinate system for formulating his double dispersion relations. The double dispersion relations were a central tool in the bootstrap program which sought to formulate a consistent theory of infinitely many particle types of increasing spin. Early life Mandelstam was born in Johannesburg, South Africa to a Jewish family.William D. Rubinstein, Michael Jolles, Hilary L. Rubinstein, ''The Palgrave Dictionary of Anglo-Jewish History'', Palgrave Macmillan (2011), p. 110 Work Mandelstam, along with Tullio Regge, did the initial development of the Regge theory of strong interaction phenomenology. He reinterpreted the analytic growth rate of the scattering amplitude as a function of the cosine of the scattering angle as the power law for the falloff of scattering amplitudes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannesburg
Johannesburg ( , , ; Zulu and xh, eGoli ), colloquially known as Jozi, Joburg, or "The City of Gold", is the largest city in South Africa, classified as a megacity, and is one of the 100 largest urban areas in the world. According to Demographia, the Johannesburg–Pretoria urban area (combined because of strong transport links that make commuting feasible) is the 26th-largest in the world in terms of population, with 14,167,000 inhabitants. It is the provincial capital and largest city of Gauteng, which is the wealthiest province in South Africa. Johannesburg is the seat of the Constitutional Court, the highest court in South Africa. Most of the major South African companies and banks have their head offices in Johannesburg. The city is located in the mineral-rich Witwatersrand range of hills and is the centre of large-scale gold and diamond trade. The city was established in 1886 following the discovery of gold on what had been a farm. Due to the extremely large gold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirac Medal
The Dirac Medal is the name of four awards in the field of theoretical physics, computational chemistry, and mathematics, awarded by different organizations, named in honour of Professor Paul Dirac, one of the great theoretical physicists of the 20th century. The Dirac Medal and Lecture (University of New South Wales) The first-established prize is the Dirac Medal for the Advancement of Theoretical Physics, awarded by the University of New South Wales, Sydney, Australia, jointly with the Australian Institute of Physics on the occasion of the public Dirac Lecture. The Lecture and the Medal commemorate the visit to the university in 1975 of Professor Dirac, who gave five lectures there. These lectures were subsequently published as a book: ''Directions of Physics'' (Wiley, 1978 – H. Hora and J. Shepanski, eds.). Professor Dirac donated the royalties from this book to the University for the establishment of the Dirac Lecture series. The prize, first awarded in 1979, includes a silv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neveu–Schwarz Sector
In mathematical physics, a super Virasoro algebra is an extension of the Virasoro algebra (named after Miguel Ángel Virasoro) to a Lie superalgebra. There are two extensions with particular importance in superstring theory: the Ramond algebra (named after Pierre Ramond) and the Neveu–Schwarz algebra (named after André Neveu and John Henry Schwarz). Both algebras have ''N'' = 1 supersymmetry and an even part given by the Virasoro algebra. They describe the symmetries of a superstring in two different sectors, called the Ramond sector and the Neveu–Schwarz sector. The ''N'' = 1 super Virasoro algebras There are two minimal extensions of the Virasoro algebra with ''N'' = 1 supersymmetry: the Ramond algebra and the Neveu–Schwarz algebra. They are both Lie superalgebras whose even part is the Virasoro algebra: this Lie algebra has a basis consisting of a central element ''C'' and generators ''L''''m'' (for integer ''m'') satisfying L_m , L_n = ( m - n ) L_ + \frac m ( m^2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Ramond
Pierre Ramond (; born 31 January 1943) is distinguished professor of physics at University of Florida in Gainesville, Florida. He initiated the development of superstring theory. Academic career Ramond completed his BSEE from Newark College of Engineering (now New Jersey Institute of Technology) in 1965 and completed his Ph.D. in physics from Syracuse University in 1969. He was a postdoctoral fellow at NAL (FermiLab) from 1969 to 1971. He became instructor at Yale University from 1971 to 1973 and assistant professor at Yale University from 1973 to 1976. He moved to Caltech as an R. A. Millikan Senior Fellow in 1976. He became a professor of physics at University of Florida in 1980, and promoted to his present title of "distinguished professor" in 1999. Superstring theory Ramond initiated the development of superstring theory. In 1970, Ramond generalized Dirac's work for point-like particles to stringlike ones. In this process he discovered two-dimensional supersymmetry and l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virasoro Algebra
In mathematics, the Virasoro algebra (named after the physicist Miguel Ángel Virasoro) is a complex Lie algebra and the unique central extension of the Witt algebra. It is widely used in two-dimensional conformal field theory and in string theory. Definition The Virasoro algebra is spanned by generators for and the central charge . These generators satisfy ,L_n0 and The factor of 1/12 is merely a matter of convention. For a derivation of the algebra as the unique central extension of the Witt algebra, see derivation of the Virasoro algebra. The Virasoro algebra has a presentation in terms of two generators (e.g. 3 and −2) and six relations. Representation theory Highest weight representations A highest weight representation of the Virasoro algebra is a representation generated by a primary state: a vector v such that : L_ v = 0, \quad L_0 v = hv, where the number is called the conformal dimension or conformal weight of v.P. Di Francesco, P. Mathieu, and D. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Veneziano Amplitude
In theoretical physics, the Veneziano amplitude refers to the discovery made in 1968 by Italian theoretical physicist Gabriele Veneziano that the Euler beta function, when interpreted as a scattering amplitude, has many of the features needed to explain the physical properties of strongly interacting mesons, such as symmetry and duality. Conformal symmetry was soon discovered. This discovery can be considered the birth of string theory, as the discovery and invention of string theory came about as a search for a physical model which would give rise to such a scattering amplitude. In particular, the amplitude appears as the four tachyon scattering amplitude in orientated open bosonic string theory. Using Mandelstam variables and the beta function B(x,y), the amplitude is given by : S(k_1,k_2,k_3,k_4) = \frac(2\pi)^\delta^(\Sigma_i k_i)\big (\alpha(s),\alpha(t))+B(\alpha(s),\alpha(u))+B(\alpha(t),\alpha(u))\big where \alpha' is the string constant, k_i are the tachyon four-vector ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gabriele Veneziano
Gabriele Veneziano (; ; born 7 September 1942) is an Italian theoretical physicist widely considered the father of string theory. He has conducted most of his scientific activities at CERN in Geneva, Switzerland, and held the Chair of Elementary Particles, Gravitation and Cosmology at the Collège de France in Paris from 2004 to 2013, until the age of retirement there. Life Gabriele Veneziano was born in Florence. In 1965, he earned his Laurea in Theoretical Physics from the University of Florence under the direction of . He pursued his doctoral studies at the Weizmann Institute of Science in Rehovot, Israel and obtained his PhD in 1967 under the supervision of Hector Rubinstein. During his stay in Israel, he collaborated, among others, with Marco Ademollo (a professor in Florence) and Miguel Virasoro (an Argentinian physicist who later became a professor in Italy). During his years at MIT, he collaborated with many colleagues and primarily with Sergio Fubini (an MIT professor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regge Theory
Regge may refer to * Tullio Regge (1931-2014), Italian physicist, developer of Regge calculus and Regge theory * Regge calculus, formalism for producing simplicial approximations of spacetimes * Regge theory, study of the analytic properties of scattering * 3778 Regge, main-belt asteroid * Regge (river) The Regge rɛɣəis a river in the Netherlands. It is a tributary to the Vecht of Overijssel. The source of the Regge is near the town Goor Goor () is a city about 20 km west of Enschede in the Dutch province of Overijssel. It received c ..., river in Overijssel, the Netherlands {{disambig, surname Surnames of Italian origin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tullio Regge
Tullio Eugenio Regge (; July 11, 1931 – October 23, 2014) was an Italian theoretical physicist. Biography Regge obtained the ''laurea'' in physics from the University of Turin in 1952 under the direction of Mario Verde and Gleb Wataghin, and a PhD in physics from the University of Rochester in 1957 under the direction of Robert Marshak. From 1958 to 1959 Regge held a post at the Max Planck Institute for Physics where he worked with Werner Heisenberg. In 1961 he was appointed to the chair of Relativity at the University of Turin. He also held an appointment at the Institute for Advanced Study from 1965 to 1979. He was emeritus professor at the Polytechnic University of Turin while contributing work at CERN as a visiting scientist. Regge died on October 23, 2014. He was married to Rosanna Cester, physicist, by whom he had three children: Daniele, Marta and Anna. In 1959, Regge discovered a mathematical property of potential scattering in the Schrödinger equation—that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hilary L
Hilary or Hillary may refer to: * Hillary Clinton, American politician * Hillary Coast, Antarctica * Hilary (name), or Hilarie or Hillary, a given name and surname * Hilary term, the spring term at the Universities of Oxford and Dublin * ''Hikari no Densetsu'', a 1985 manga series, known in Italian as ''Hilary'' * Hurricane Hilary, the name of several storms * ''Hillary'' (film), a 2020 American documentary film about Hillary Clinton * HMS ''Hilary'' See also * Hillery (other) * Saint Hilary (other) * Saint-Hilaire (other) * Ilar (other), Welsh form of the name Hilary * Eleri (other) Eleri (the Welsh form of the masculine given name Hilarus or Hilarius) may refer to: * Pope Saint Hilarius (5th century) in Welsh contexts * Eleri, daughter of Brychan Brycheiniog, the Welsh, 5th-century king * Saint Eleri (7th century), Welsh pri ..., Welsh form of the name Hilarus * Hillarys, Western Australia {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William D
William is a male given name of Germanic origin.Hanks, Hardcastle and Hodges, ''Oxford Dictionary of First Names'', Oxford University Press, 2nd edition, , p. 276. It became very popular in the English language after the Norman conquest of England in 1066,All Things William"Meaning & Origin of the Name"/ref> and remained so throughout the Middle Ages and into the modern era. It is sometimes abbreviated "Wm." Shortened familiar versions in English include Will, Wills, Willy, Willie, Bill, and Billy. A common Irish form is Liam. Scottish diminutives include Wull, Willie or Wullie (as in Oor Wullie or the play ''Douglas''). Female forms are Willa, Willemina, Wilma and Wilhelmina. Etymology William is related to the given name ''Wilhelm'' (cf. Proto-Germanic ᚹᛁᛚᛃᚨᚺᛖᛚᛗᚨᛉ, ''*Wiljahelmaz'' > German '' Wilhelm'' and Old Norse ᚢᛁᛚᛋᛅᚼᛅᛚᛘᛅᛋ, ''Vilhjálmr''). By regular sound changes, the native, inherited English form of the name shou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bootstrap Model
The term "bootstrap model" is used for a class of theories that use very general consistency criteria to determine the form of a quantum theory from some assumptions on the spectrum of particles. It is a form of S-matrix theory. Overview In the 1960s and '70s, the ever-growing list of strongly interacting particles — mesons and baryons — made it clear to physicists that none of these particles is elementary. Geoffrey Chew and others went so far as to question the distinction between composite and elementary particles, advocating a "nuclear democracy" in which the idea that some particles were more elementary than others was discarded. Instead, they sought to derive as much information as possible about the strong interaction from plausible assumptions about the S-matrix, which describes what happens when particles of any sort collide, an approach advocated by Werner Heisenberg two decades earlier. The reason the program had any hope of success was because of crossin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
