String theory

In quantum field theory and statistical mechanics, the 1/N expansion is a particular perturbative analysis of quantum field theories with an SO(N) or SU(N) internal symmetry. ...more on Wikipedia about "1/N expansion"

In physics, the AdS/CFT correspondence is the equivalence between a string theory (or some other theory of quantum gravity like supergravity) defined on anti de Sitter space (AdS) (or the product of anti de Sitter space (AdS) with some closed manifold/ orbifold/ noncommutative space), and a conformal field theory (CFT) defined on the conformal boundary of this AdS space, whose dimension is lower by one. An example is the duality between Type IIB string theory defined on AdS₅ x S⁵ space (a product of five dimensional AdS space with a five dimensional sphere) and a Supersymmetric N=4 Yang-Mills gauge theory defined on the 4-dimensional boundary of AdS₅. It is the most successfully tested realization of the holographic principle, a speculative idea about quantum gravity originally proposed by Gerard 't Hooft and improved and promoted by Leonard Susskind. ...more on Wikipedia about "AdS/CFT correspondence"

In theoretical physics, the AdS/QCD correspondence is a program to describe Quantum Chromodynamics (QCD) in terms of a dual gravitational theory, following the principles of the AdS/CFT correspondence in a setup where the quantum field theory is not a conformal field theory. ...more on Wikipedia about "AdS/QCD"

Bosonic string theory is the original version of string theory, developed in the late 1960s. Although it has many attractive features, it also predicts a particle called the tachyon possessing some unsettling properties, and it has no fermions. All of its particles are bosons, that determines the name. The physicists have also calculated that bosonic string theory requires 26 spacetime dimensions: 25 spatial dimensions and one dimension of time. ...more on Wikipedia about "Bosonic string theory"

Branes are objects in M-theory and its offshoot, brane cosmology. ...more on Wikipedia about "Brane"

In mathematics, a Calabi-Yau manifold is a compact Kähler manifold with a vanishing first Chern class. A Calabi-Yau manifold of complex dimension n is also called a Calabi-Yau n-fold. The mathematician Eugenio Calabi conjectured in 1957 that all such manifolds admit a Ricci-flat metric (one in each Kähler class), and this conjecture was proved by Shing-Tung Yau in 1977 and became Yau's theorem. Consequently, a Calabi-Yau manifold can also be defined as a compact Ricci-flat Kähler manifold. ...more on Wikipedia about "Calabi-Yau manifold"

In theoretical physics, the Chan-Paton factor is a multivalued index associated with the endpoints of an open string. An open string can be interpreted as a fluxtube connecting a quark and its antiparticle. The two Chan-Paton factors make the string transform as a tensor under a gauge group whose charges are carried by the endpoints of the strings. ...more on Wikipedia about "Chan-Paton factor" Everybody should like www.shortopedia.com

In physics, compactification plays an important part in string theory. ...more on Wikipedia about "Compactification (physics)"

Conformal anomaly is an anomaly i.e. a quantum phenomenon that breaks the conformal symmetry of the classical theory. ...more on Wikipedia about "Conformal anomaly"

In mathematics, a conifold is a generalization of the notion of a manifold. Unlike manifolds, a conifold can (or should) contain conical singularities i.e. points whose neighborhood looks like a cone with a certain base. The base is usually a five- dimensional manifold. ...more on Wikipedia about "Conifold"

In the renormalization group analysis of phase transitions in physics, a critical dimension is the dimensionality of space at which the character of the phase transition changes. Below the lower critical dimension there is no phase transition. Above the upper critical dimension the critical indices of the theory become the same as that in mean field theory. ...more on Wikipedia about "Critical dimension"

In particle physics, the crypton is a hypothetical superheavy particle, thought to exist in a hidden sector of string theory. It has been proposed as a candidate particle to explain the dark matter content of the universe. ...more on Wikipedia about "Crypton"

The cyclic model is a brane cosmology model of the creation of the universe, derived from the earlier ekpyrotic model. It was proposed in 2001 by Paul Steinhardt and Neil Turok. ...more on Wikipedia about "Cyclic model"

In theoretical physics, D-branes are a special class of p-branes, named for the physicist Johann Dirichlet. Dirichlet boundary conditions have long been used in the study of fluids and potential theory, where they involve specifying some quantity all along a boundary. In fluid dynamics, fixing a Dirichlet boundary condition could mean assigning a known fluid velocity to all points on a surface; when studying electrostatics, one may establish Dirichlet boundary conditions by fixing the voltage to known values at particular locations, like the surfaces of conductors. In either case, the locations at which values are specified is called a D-brane. These constructions take on special importance in string theory, because open strings must have their endpoints attached to D-branes. ...more on Wikipedia about "D-brane"

In theoretical physics, dilaton originally referred to a theoretical scalar field; as a photon refers in one sense to the electromagnetic field. For the dilaton, also known as the radion or graviscalar, it is the scalar field which appears in Kaluza-Klein theory—as the component ...more on Wikipedia about "Dilaton"

A domain wall is a term in physics which can have one of two distinct meanings in either string theory or magnetism. Domain wall is also used as technobabble in science fiction. ...more on Wikipedia about "Domain wall"

Dp-brane is how D-branes (special P-branes) are referred to, by spatial dimensionality (p) D is the type of brane and p can range from 0-25. 0 being a point, 1 being a line, and so on. ...more on Wikipedia about "Dp-brane"

In theoretical physics, the term dual resonance models refers to the early investigation (1968-1974 or so) of the subject that is currently known as string theory. ...more on Wikipedia about "Dual resonance model"

In physics, in the context of string theory, F-theory is formally a 12-dimensional theory, but the only way to obtain an acceptable background is to compactify this theory on a two-torus. By doing so, we obtain type IIB superstring theory in 10 dimensions. The SL(2,Z) S-duality symmetry of the resulting type IIB string theory is manifest because it arises as the group of large diffeomorphisms of the two-dimensional torus. ...more on Wikipedia about "F-theory"

In physics, the first superstring revolution is a period of important discoveries in string theory roughly between 1984 and 1986. The physicists realized that string theory was capable to describe all elementary particles and interactions between them, and hundreds of them started to work on string theory as the most promising idea to unify theories of physics. The revolution was started by a discovery of anomaly cancellation in type I string theory by Michael Green and John Schwarz in 1984. The anomaly is cancelled due to the Green-Schwarz mechanism. Several other ground-breaking discoveries, such as the heterotic string, were made in 1985. It was also realised in 1985 that to obtain $N=1$ supersymmetry, the six small extra dimensions need to be compactified on a Calabi-Yau manifold. ...more on Wikipedia about "First superstring revolution"

Fuzzballs, also called Stringy Stars, are String Theory's equivalent of black holes. In recent years physicists have delved into how strings could interconnect to create black holes; the result are large, very flaccid discs, which would not have a point sized singularity that is the essence of the modern black hole. ...more on Wikipedia about "Fuzzballs"

In mathematics, and in particular, in the mathematical background of string theory, the Goddard-Thorn theorem (also called the no-ghost theorem) is a theorem about certain vector spaces. It is named after P. Goddard and C. B. Thorn. ...more on Wikipedia about "Goddard-Thorn theorem"

In physics, the graviton is a hypothetical elementary particle that transmits the force of gravity in most quantum gravity systems. In order to do this, one theory posits that gravitons have to be always-attractive (gravity never pushes), work over any distance (gravity is universal) and come in unlimited numbers (to provide high strengths near stars). In quantum theory, these requirements define an even- spin (spin 2 in this case) boson with a rest mass of zero. ...more on Wikipedia about "Graviton"

In mathematics, specifically in symplectic topology and algebraic geometry, Gromov-Witten (GW) invariants are rational numbers that count pseudoholomorphic curves meeting prescribed conditions in a given symplectic manifold. The GW invariants may be packaged as a homology or cohomology class in an appropriate space, or as the deformed cup product of quantum cohomology. These invariants have been used to distinguish symplectic manifolds; they also play a crucial role in type IIA string theory. ...more on Wikipedia about "Gromov-Witten invariant"

In theoretical physics, the Hagedorn temperature is the maximal allowed temperature of certain systems above which the partition sum diverges. ...more on Wikipedia about "Hagedorn temperature"

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