1.
String theory
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In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects called strings. It describes how strings propagate through space and interact with each other. On distance scales larger than the scale, a string looks just like an ordinary particle, with its mass, charge. In string theory, one of the vibrational states of the string corresponds to the graviton. Thus string theory is a theory of quantum gravity, String theory is a broad and varied subject that attempts to address a number of deep questions of fundamental physics. Despite much work on problems, it is not known to what extent string theory describes the real world or how much freedom the theory allows to choose the details. String theory was first studied in the late 1960s as a theory of the nuclear force. Subsequently, it was realized that the properties that made string theory unsuitable as a theory of nuclear physics made it a promising candidate for a quantum theory of gravity. The earliest version of string theory, bosonic string theory, incorporated only the class of known as bosons. It later developed into superstring theory, which posits a connection called supersymmetry between bosons and the class of particles called fermions. In late 1997, theorists discovered an important relationship called the AdS/CFT correspondence, one of the challenges of string theory is that the full theory does not have a satisfactory definition in all circumstances. Another issue is that the theory is thought to describe an enormous landscape of possible universes, and these issues have led some in the community to criticize these approaches to physics and question the value of continued research on string theory unification. In the twentieth century, two theoretical frameworks emerged for formulating the laws of physics, one of these frameworks was Albert Einsteins general theory of relativity, a theory that explains the force of gravity and the structure of space and time. The other was quantum mechanics, a different formalism for describing physical phenomena using probability. In spite of successes, there are still many problems that remain to be solved. One of the deepest problems in physics is the problem of quantum gravity. The general theory of relativity is formulated within the framework of classical physics, in addition to the problem of developing a consistent theory of quantum gravity, there are many other fundamental problems in the physics of atomic nuclei, black holes, and the early universe. String theory is a framework that attempts to address these questions
2.
AdS/CFT correspondence
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On one side are anti-de Sitter spaces which are used in theories of quantum gravity, formulated in terms of string theory or M-theory. On the other side of the correspondence are conformal field theories which are quantum field theories, the duality represents a major advance in our understanding of string theory and quantum gravity. It also provides a toolkit for studying strongly coupled quantum field theories. This fact has been used to study aspects of nuclear. The AdS/CFT correspondence was first proposed by Juan Maldacena in late 1997, important aspects of the correspondence were elaborated in articles by Steven Gubser, Igor Klebanov, and Alexander Markovich Polyakov, and by Edward Witten. By 2015, Maldacenas article had over 10,000 citations and our current understanding of gravity is based on Albert Einsteins general theory of relativity. Formulated in 1915, general relativity explains gravity in terms of the geometry of space and time and it is formulated in the language of classical physics developed by physicists such as Isaac Newton and James Clerk Maxwell. The other nongravitational forces are explained in the framework of quantum mechanics, developed in the first half of the twentieth century by a number of different physicists, quantum mechanics provides a radically different way of describing physical phenomena based on probability. Quantum gravity is the branch of physics that seeks to describe gravity using the principles of quantum mechanics, currently, the most popular approach to quantum gravity is string theory, which models elementary particles not as zero-dimensional points but as one-dimensional objects called strings. In the AdS/CFT correspondence, one typically considers theories of quantum gravity derived from string theory or its modern extension, in everyday life, there are three familiar dimensions of space, and there is one dimension of time. Thus, in the language of physics, one says that spacetime is four-dimensional. The quantum gravity theories appearing in the AdS/CFT correspondence are typically obtained from string and this produces a theory in which spacetime has effectively a lower number of dimensions and the extra dimensions are curled up into circles. A standard analogy for compactification is to consider an object such as a garden hose. Thus, an ant crawling inside it would move in two dimensions, the application of quantum mechanics to physical objects such as the electromagnetic field, which are extended in space and time, is known as quantum field theory. In particle physics, quantum field theories form the basis for our understanding of elementary particles, quantum field theories are also used throughout condensed matter physics to model particle-like objects called quasiparticles. In the AdS/CFT correspondence, one considers, in addition to a theory of quantum gravity and this is a particularly symmetric and mathematically well behaved type of quantum field theory. In the AdS/CFT correspondence, one considers string theory or M-theory on an anti-de Sitter background and this means that the geometry of spacetime is described in terms of a certain vacuum solution of Einsteins equation called anti-de Sitter space. It is closely related to space, which can be viewed as a disk as illustrated on the right
3.
David Gross
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David Jonathan Gross is an American theoretical physicist and string theorist. Along with Frank Wilczek and David Politzer, he was awarded the 2004 Nobel Prize in Physics for their discovery of asymptotic freedom. He is the director and current holder of the Frederick W. Gluck Chair in Theoretical Physics at the Kavli Institute for Theoretical Physics of the University of California. He is also a faculty member in the UC Santa Barbara Physics Department and is affiliated with the Institute for Quantum Studies at Chapman University in California. He is the Foreign Member of Chinese Academy of Sciences, Gross was born to a Jewish family in Washington, D. C. in February 19,1941. His parents were Nora and Bertram Myron Gross, Gross received his bachelors degree and masters degree from the Hebrew University of Jerusalem, Israel, in 1962. He received his Ph. D. in physics from the University of California, Berkeley and he was a Junior Fellow at Harvard University and a Professor at Princeton University until 1997. He was the recipient of a MacArthur Foundation Fellowship in 1987, the Dirac Medal in 1988, asymptotic freedom, independently discovered by Politzer, was important for the development of quantum chromodynamics. Gross, with Jeffrey A. Harvey, Emil Martinec, the four were to be whimsically nicknamed the Princeton String Quartet. In 2003, Gross was one of 22 Nobel Laureates who signed the Humanist Manifesto and they have two children, Ariela Gross, who is an historian and professor of law at the University of Southern California and the mother of his grandchildren, Raphaela and Sophia. Elisheva Gross, who received a Doctor in psychology at the University of California at Los Angeles and his second wife is Jacquelyn Savani. He has a stepdaughter, Miranda Savani, in Santa Barbara, California
4.
Willy Fischler
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Willy Fischler is a theoretical physicist. He is the Jane and Roland Blumberg Centennial Professor of Physics at the University of Texas at Austin and his contributions to physics include, Early computation of the force between heavy quarks. The invisible axion, as a solution to the strong CP problem, the cosmological effects of the invisible axion and its role as a candidate for dark matter. Pioneering work on the use of supersymmetry to solve outstanding problems in the model of particle physics. The first formulation of what became known as the problem in cosmology”. The Fischler-Susskind mechanism in string theory, the original formulation of the holographic entropy bound in the context of cosmology. The discovery of M theory, or BFSS Matrix Theory, M theory is an example of a gauge/gravity duality. He is a Licensed Paramedic with Marble Falls Area EMS and was a volunteer EMT with the Westlake Fire Department
5.
Quantum gravity
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Quantum gravity is a field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics, and where quantum effects cannot be ignored. The current understanding of gravity is based on Albert Einsteins general theory of relativity, the necessity of a quantum mechanical description of gravity is sometimes said to follow from the fact that one cannot consistently couple a classical system to a quantum one. This is false as is shown, for example, by Walds explicit construction of a consistent semiclassical theory, the problem is that the theory one gets in this way is not renormalizable and therefore cannot be used to make meaningful physical predictions. As a result, theorists have taken up more radical approaches to the problem of quantum gravity, a theory of quantum gravity that is also a grand unification of all known interactions is sometimes referred to as The Theory of Everything. As a result, quantum gravity is a mainly theoretical enterprise, much of the difficulty in meshing these theories at all energy scales comes from the different assumptions that these theories make on how the universe works. Quantum field theory, if conceived of as a theory of particles, General relativity models gravity as a curvature within space-time that changes as a gravitational mass moves. Historically, the most obvious way of combining the two ran quickly into what is known as the renormalization problem, another possibility is to focus on fields rather than on particles, which are just one way of characterizing certain fields in very special spacetimes. This solves worries about consistency, but does not appear to lead to a version of full general theory of relativity. Quantum gravity can be treated as a field theory. Effective quantum field theories come with some high-energy cutoff, beyond which we do not expect that the theory provides a description of nature. The infinities then become large but finite quantities depending on this finite cutoff scale and this same logic works just as well for the highly successful theory of low-energy pions as for quantum gravity. Indeed, the first quantum-mechanical corrections to graviton-scattering and Newtons law of gravitation have been explicitly computed. In fact, gravity is in ways a much better quantum field theory than the Standard Model. Specifically, the problem of combining quantum mechanics and gravity becomes an issue only at high energies. This problem must be put in the context, however. While there is no proof of the existence of gravitons. The predicted find would result in the classification of the graviton as a force similar to the photon of the electromagnetic field. Many of the notions of a unified theory of physics since the 1970s assume, and to some degree depend upon
6.
T-duality
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In theoretical physics, T-duality is an equivalence of two physical theories, which may be either quantum field theories or string theories. The two theories are equivalent in the sense that all observable quantities in one description are identified with quantities in the dual description. For example, momentum in one description takes discrete values and is equal to the number of times the string winds around the circle in the dual description, the idea of T-duality can be extended to more complicated theories, including superstring theories. The existence of these dualities implies that seemingly different superstring theories are actually physically equivalent and this led to the realization, in the mid-1990s, that all of the five consistent superstring theories are just different limiting cases of a single eleven-dimensional theory called M-theory. In general, T-duality relates two theories with different spacetime geometries, in this way, T-duality suggests a possible scenario in which the classical notions of geometry break down in a theory of Planck scale physics. The geometric relationships suggested by T-duality are also important in pure mathematics, T-duality is a particular example of a general notion of duality in physics. The term duality refers to a situation where two different physical systems turn out to be equivalent in a nontrivial way. If two theories are related by a duality, it means that one theory can be transformed in some way so that it ends up looking just like the other theory, the two theories are then said to be dual to one another under the transformation. Put differently, the two theories are different descriptions of the same phenomena. Like many of the dualities studied in physics, T-duality was discovered in the context of string theory. In string theory, particles are modeled not as zero-dimensional points, the physics of strings can be studied in various numbers of dimensions. In addition to three dimensions from everyday experience, string theories may include one or more compact dimensions which are curled up into circles. A standard analogy for this is to consider multidimensional object such as a garden hose, if the hose is viewed from a sufficient distance, it appears to have only one dimension, its length. However, as one approaches the hose, one discovers that it contains a second dimension, thus, an ant crawling inside it would move in two dimensions. Such extra dimensions are important in T-duality, which relates a theory in which strings propagate on a circle of some radius R to a theory in which strings propagate on a circle of radius 1 / R. In mathematics, the number of a curve in the plane around a given point is an integer representing the total number of times that curve travels counterclockwise around the point. The notion of winding number is important in the description of T-duality where it is used to measure the winding of strings around compact extra dimensions. For example, the image below shows examples of curves in the plane
7.
Nima Arkani-Hamed
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Nima Arkani-Hamed is an American-Canadian of Iranian descent, who is a theoretical physicist with interests in high-energy physics, string theory and cosmology. Arkani-Hamed is now on the faculty at the Institute for Advanced Study in Princeton, New Jersey and he was formerly a professor at Harvard University and the University of California, Berkeley. Arkani-Hameds parents, Jafargholi Jafar Arkani-Hamed and Hamideh Alasti are both physicists from Iran and his father, a native of Tabriz, was chairman of the physics department at Sharif University of Technology in Tehran, and later taught earth and planetary sciences at McGill University in Montreal. Arkani-Hamed immigrated to Canada as a child with his family, the majority of his graduate work was on studies of supersymmetry and flavor physics. His Ph. D dissertation was titled Supersymmetry and Hierarchies and he completed his Ph. D in 1997 and went to SLAC at Stanford University for post-doctoral studies. During this time he worked with Savas Dimopoulos and developed the paradigm of large extra dimensions, in 1999 he joined the faculty of the University of California, Berkeley physics department. He took a leave of absence from Berkeley to visit Harvard University beginning January 2001, shortly after arriving at Harvard he worked with Howard Georgi and Andrew Cohen on the idea of emergent extra dimensions, dubbed dimensional deconstruction. These ideas eventually led to the development of little Higgs theories and he officially joined Harvards faculty in the fall of 2002. Arkani-Hamed has appeared on television programs and newspapers talking about space, time and dimensions. In 2003 he won the Gribov Medal of the European Physical Society and he appeared in the 2013 documentary film Particle Fever. He participated in the Stock Exchange of Visions project in 2007, in 2008, he won the Raymond and Beverly Sackler Prize given at Tel Aviv University to young scientists who have made outstanding and fundamental contributions in Physical Science. Arkani-Hamed was elected a Fellow of the American Academy of Arts, in 2010, he gave the Messenger lectures at Cornell University. Nima Arkani-Hamed was a professor at Harvard University from 2002–2008, and is now at the Institute for Advanced Study, Arkani-Hamed was selected for being a member of The Selection Committee for the 2015 Breakthrough Prize in Fundamental Physics. In July 2012, he was an awardee of the Fundamental Physics Prize. He has previously won the Sackler Prize from Tel Aviv University in 2008, the Gribov Medal from the European Physical Society in 2003, and he was awarded the Packard and Sloan Fellowship in 2000. The paradigm of large dimensions, N. Arkani-Hamed, S. Dimopoulos. The Hierarchy Problem and New Dimensions at a Millimeter, I Antoniadis, N. Arkani-Hamed, S. Dimopoulos, G. Dvali. New Dimensions at a Millimeter to a Fermi and Superstrings at a TeV, N. Arkani-Hamed, S. Dimopoulos, G. Dvali
8.
Robbert Dijkgraaf
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Robertus Henricus Robbert Dijkgraaf is a Dutch mathematical physicist and string theorist. He is tenured professor at the University of Amsterdam, and director, robertus Henricus Dijkgraaf was born on 24 January 1960 in Ridderkerk, Netherlands. He lives in Princeton, New Jersey, Dijkgraaf is married to the author Pia de Jong and has three children. Dijkgraaf went to Erasmiaans Gymnasium in Rotterdam, Netherlands and he started his education in physics at Utrecht University in 1978. After completing his Bachelors degree equivalent in 1982 he briefly turned away from physics to pursue painting at the Gerrit Rietveld Academie, in 1984, he returned to Utrecht University, to start on his masters degree in theoretical physics. After obtaining his MSc degree, he continued working towards his PhD under supervision of Nobel laureate Gerard t Hooft and he studied together with the twins Erik and Herman Verlinde. The original arrangement was only one of the trio would work on string theory. Dijkgraaf obtained his doctorate in 1989 cum laude and his thesis was titled A Geometrical Approach to Two Dimensional Conformal Field Theory. Subsequently, Dijkgraaf held positions at Princeton University and the Institute for Advanced Study, in 1992, he was appointed professor at the University of Amsterdam, where he held the chair of mathematical physics until 2004, when he was appointed distinguished professor at the same university. He regularly appears on Dutch television and has a column in the Dutch newspaper NRC Handelsblad, from 2008 to 2012 he was president of the Royal Netherlands Academy of Arts and Sciences. He was elected as one of the two co-chairs of the InterAcademy Council for the period 2009-2013, starting 1 July 2012 Dijkgraaf became the director of the Institute for Advanced Study in Princeton. On that date he stepped down from his position as president of the Royal Netherlands Academy of Arts, Robbert Dijkgraaf is a member of the CuriosityStream Advisory Board. In 2003, Dijkgraaf was awarded the Spinoza Prize, in doing so he became the first recipient of the award whose advisor also was a recipient. He used part of his Spinoza Prize grant to set up a website targeted at children and promoting science, Dijkgraaf is a member of the Royal Netherlands Academy of Arts and Sciences since 2003 and the Royal Holland Society of Sciences and Humanities. On 5 June 2012 he was made a Knight of the Order of the Netherlands Lion, in 2012 he became a fellow of the American Mathematical Society. Dijkgraafs research focuses on string theory and the interface of mathematics and physics in general and he is best known for his work on topological string theory and matrix models, and his name has been given to the Dijkgraaf-Witten invariants and the Witten-Dijkgraaf-Verlinde-Verlinde formula. Blikwisselingen Het nut van nutteloos onderzoek Robbert Dijkgraaf, official website Robbert Dijkgraaf, profile at the IAS website Quantum Questions Inspire New Math, Quanta Magazine, March 30,2017
9.
Michael Duff (physicist)
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Duff completed his Bachelor of Science in Physics Queen Mary College, London in 1969. He then went on to his Doctor of Philosophy in theoretical physics in 1972 at Imperial College London supervised by the Nobel Laureate Abdus Salam. He did postdoctoral fellowships at the International Centre for Theoretical Physics, University of Oxford, Kings College London, Queen Mary College London, after his postdoctoral fellowships, he returned to Imperial College in 1979 on a Science Research Council Advanced Fellowship and joined the faculty there in 1980. He took leave of absence to visit the Theory Division in CERN, first in 1982 and he took up his professorship at Texas A&M University in 1988 and was appointed Distinguished Professor in 1992. In 1999 he moved to the University of Michigan, where he was Oskar Klein Professor of Physics, in 2001, he was elected first Director of the Michigan Center for Theoretical Physics and was re-elected in 2004. He returned again to Imperial College, London and became Professor of Physics and he was appointed Abdus Salam Professor of Theoretical Physics in 2006. His interests lie in unified theories of the particles, quantum gravity, supergravity, Kaluza–Klein theory, superstrings, supermembranes. He is the author of The World in Eleven Dimensions, Supergravity, Supermembranes and M-theory, Imperial College faculty page for Duff Duffs web site Duff, M. J. Recent applications of the Weyl Anomaly, prof. Michael Duff presented and published his paper in National Center for Physics in Islamabad, Pakistan. Scientific publications of Michael Duff on INSPIRE-HEP
10.
Sylvester James Gates
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Sylvester James Gates Jr. known as S. James Gates Jr. or Jim Gates, is an American theoretical physicist, known for work on supersymmetry, supergravity, and superstring theory. Gates received BS and PhD degrees from the Massachusetts Institute of Technology and his doctoral thesis was the first at MIT on supersymmetry. With M. T. Grisaru, M. Rocek and W. Siegel, Gates coauthored Superspace, or One thousand and one lessons in supersymmetry and he is on the board of trustees of Society for Science & the Public. Gates was a Martin Luther King Jr, visiting Scholar at MIT and was a Residential Scholar at MITs Simmons Hall. He is pursuing ongoing research into string theory, supersymmetry, and his research focuses on Adinkra symbols as representations of supersymmetric algebras. On February 1,2013, Gates was a recipient of the National Medal of Science, Gates was elected to the National Academy of Sciences in 2013. On November 5,2016, Gates spoke at the 2016 Quadrennial Physics Congress, recently Gates has been featured in a TurboTax commercial and has been featured extensively on NOVA PBS programs on physics, notably The Elegant Universe. During the 2008 World Science Festival, Gates narrated a ballet The Elegant Universe, Gates Appeared on the 2011 Isaac Asimov Memorial Debate, The Theory of Everything, hosted by Neil DeGrasse Tyson. Gates also appeared in the BBC Horizon documentary The Hunt for Higgs in 2012, Gates recently appeared in another NOVA documentary Big Bang Machine in 2015. Superspace or 1001 Lessons in Supersymmetry, Benjamin-Cummings Publishing Company, Reading, larte della fisica superspace, Stringhe, superstringhe, teoria unificata dei campi,2006, Di Renzo Editore, ISBN 88-8323-155-4. Appearances on C-SPAN Sylvester James Gates at the Internet Movie Database