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List Of Quantum Field Theories
This is a list of quantum field theories. The first few sections are organized according to their matter content, that is, the types of fields appearing in the theory. This is just one of many ways to organize quantum field theories, but reflects the way the subject is taught pedagogically. Scalar field theory Theories whose matter content consists of only scalar fields * Klein-Gordon: free scalar field theory * φ4 theory * Sine-Gordon *Toda field theory Spinor field theory Theories whose matter content consists only of spinor fields * Dirac theory: free spinor field theory *Thirring model *Nambu–Jona-Lasinio model *Gross–Neveu model Gauge field theory Theories whose matter content consists only of gauge fields *Yang–Mills theory * Proca theory *Chern–Simons theory Interacting theories *Spinor and scalar ** Yukawa model *Scalar and gauge ** Scalar electrodynamics ** Scalar chromodynamics ** Yang–Mills–Higgs *Spinor and gauge **Quantum electrodynamics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Field Theory
In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines classical field theory, special relativity, and quantum mechanics. QFT is used in particle physics to construct physical models of subatomic particles and in condensed matter physics to construct models of quasiparticles. QFT treats particles as excited states (also called Quantum, quanta) of their underlying quantum field (physics), fields, which are more fundamental than the particles. The equation of motion of the particle is determined by minimization of the Lagrangian, a functional of fields associated with the particle. Interactions between particles are described by interaction terms in the Lagrangian (field theory), Lagrangian involving their corresponding quantum fields. Each interaction can be visually represented by Feynman diagrams according to perturbation theory (quantum mechanics), perturbation theory in quantum mechanics. History Quantum field theory emerged from the wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6D (2,0) Superconformal Field Theory
In theoretical physics, the six-dimensional (2,0)-superconformal field theory is a quantum field theory whose existence is predicted by arguments in string theory. It is still poorly understood because there is no known description of the theory in terms of an action functional. Despite the inherent difficulty in studying this theory, it is considered to be an interesting object for a variety of reasons, both physical and mathematical. Applications The (2,0)-theory has proven to be important for studying the general properties of quantum field theories. Indeed, this theory subsumes a large number of mathematically interesting effective quantum field theories and points to new dualities relating these theories. For example, Luis Alday, Davide Gaiotto, and Yuji Tachikawa showed that by compactifying this theory on a surface, one obtains a four-dimensional quantum field theory, and there is a duality known as the AGT correspondence which relates the physics of this theory to cert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ABJM Superconformal Field Theory
In theoretical physics, ABJM theory is a quantum field theory studied by Ofer Aharony, Oren Bergman, Daniel Jafferis, and Juan Maldacena. It provides a holographic dual to M-theory on AdS_4\times S^7. The ABJM theory is also closely related to Chern–Simons theory The Chern–Simons theory is a 3-dimensional topological quantum field theory of Schwarz type developed by Edward Witten. It was discovered first by mathematical physicist Albert Schwarz. It is named after mathematicians Shiing-Shen Chern and Jam ..., and it serves as a useful toy model for solving problems that arise in condensed matter physics.Aharony et al. 2008 It is a theory defined on d = 3, \mathcal = 6 superspace. See also * 6D (2,0) superconformal field theory Notes References * * Conformal field theory Supersymmetric quantum field theory String theory {{string-theory-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N = 4 Supersymmetric Yang–Mills Theory
''N'' = 4 supersymmetric Yang–Mills (SYM) theory is a mathematical and physical model created to study particles through a simple system, similar to string theory, with conformal symmetry. It is a simplified toy theory based on Yang–Mills theory that does not describe the real world, but is useful because it can act as a proving ground for approaches for attacking problems in more complex theories. It describes a universe containing bosonic field, boson fields and fermion fields which are related by four Supersymmetry, supersymmetries (this means that swapping boson, fermion and scalar fields in a certain way leaves the predictions of the theory invariant). It is one of the simplest (because it has no free parameters except for the gauge group) and one of the few finite quantum field theories in 4 dimensions. It can be thought of as the most symmetric field theory that does not involve gravity. Meaning of ''N'' and numbers of fields In ''N'' supersymmetric Yang– ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super QCD
In theoretical physics, super QCD is a supersymmetric gauge theory which resembles quantum chromodynamics (QCD) but contains additional particles and interactions which render it supersymmetry, supersymmetric. The most commonly used version of super QCD is in 4 dimensions and contains one Majorana spinor supercharge. The particle content consists of vector superfield, vector supermultiplets, which include gluons and gluinos and also chiral superfield, chiral supermultiplets which contain quarks and squarks transforming in the fundamental representation of the gauge group. This theory has many features in common with real world QCD, for example in some phases it manifests color confinement, confinement and chiral symmetry breaking. The supersymmetry of this theory means that, unlike QCD, one may use nonrenormalization theorems to analytically demonstrate the existence of these phenomena and even calculate the vacuum expectation value, condensate which breaks the chiral symmetry. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seiberg–Witten Theory
In theoretical physics, Seiberg–Witten theory is a theory that determines an exact low-energy effective action (for massless degrees of freedom) of a \mathcal = 2 supersymmetric gauge theory—namely the metric of the moduli space of vacua. Seiberg–Witten curves In general, effective Lagrangians of supersymmetric gauge theories are largely determined by their holomorphic properties and their behavior near the singularities. In particular, in gauge theory with \mathcal = 2 extended supersymmetry, the moduli space of vacua is a special Kähler manifold and its Kähler potential is constrained by above conditions. In the original approach, by Seiberg and Witten, holomorphy and electric-magnetic duality constraints are strong enough to almost uniquely constrain the prepotential, and therefore the metric of the moduli space of vacua, for theories with SU(2) gauge group. More generally, consider the example with gauge group SU(n). The classical potential is This vanishes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supersymmetric Yang–Mills
In a supersymmetric theory the equations for force and the equations for matter are identical. In theoretical and mathematical physics, any theory with this property has the principle of supersymmetry (SUSY). Dozens of supersymmetric theories exist. Supersymmetry is a spacetime symmetry between two basic classes of particles: bosons, which have an integer-valued spin and follow Bose–Einstein statistics, and fermions, which have a half-integer-valued spin and follow Fermi–Dirac statistics. In supersymmetry, each particle from one class would have an associated particle in the other, known as its superpartner, the spin of which differs by a half-integer. For example, if the electron exists in a supersymmetric theory, then there would be a particle called a ''"selectron"'' (superpartner electron), a bosonic partner of the electron. In the simplest supersymmetry theories, with perfectly " unbroken" supersymmetry, each pair of superpartners would share the same mass and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wess–Zumino Model
In theoretical physics, the Wess–Zumino model has become the first known example of an interacting four-dimensional quantum field theory with linearly realised supersymmetry. In 1974, Julius Wess and Bruno Zumino studied, using modern terminology, dynamics of a single chiral superfield (composed of a complex scalar and a spinor fermion) whose cubic superpotential leads to a renormalizable theory. The treatment in this article largely follows that of Figueroa-O'Farrill's lectures on supersymmetry, and to some extent of Tong. The model is an important model in supersymmetric quantum field theory. It is arguably the simplest supersymmetric field theory in four dimensions, and is ungauged. The Wess–Zumino action Preliminary treatment Spacetime and matter content In a preliminary treatment, the theory is defined on flat spacetime (Minkowski space). For this article, the metric has ''mostly plus'' signature. The matter content is a real scalar field S, a real pseudoscala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wess–Zumino–Witten Model
In theoretical physics and mathematics, a Wess–Zumino–Witten (WZW) model, also called a Wess–Zumino–Novikov–Witten model, is a type of two-dimensional conformal field theory named after Julius Wess, Bruno Zumino, Sergei Novikov and Edward Witten. A WZW model is associated to a Lie group (or supergroup), and its symmetry algebra is the affine Lie algebra built from the corresponding Lie algebra (or Lie superalgebra). By extension, the name WZW model is sometimes used for any conformal field theory whose symmetry algebra is an affine Lie algebra. Action Definition For \Sigma a Riemann surface, G a Lie group, and k a (generally complex) number, let us define the G-WZW model on \Sigma at the level k. The model is a nonlinear sigma model whose action is a functional of a field \gamma:\Sigma \to G: :S_k(\gamma)= -\frac \int_ d^2x\, \mathcal \left (\gamma^ \partial^\mu \gamma, \gamma^ \partial_\mu \gamma \right ) + 2\pi k S^(\gamma). Here, \Sigma is equipped with a flat Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-linear Sigma Model
In quantum field theory, a nonlinear ''σ'' model describes a scalar field which takes on values in a nonlinear manifold called the target manifold ''T''. The non-linear ''σ''-model was introduced by , who named it after a field corresponding to a spinless meson called ''σ'' in their model. This article deals primarily with the quantization of the non-linear sigma model; please refer to the base article on the sigma model for general definitions and classical (non-quantum) formulations and results. Description The target manifold ''T'' is equipped with a Riemannian metric ''g''. is a differentiable map from Minkowski space ''M'' (or some other space) to ''T''. The Lagrangian density in contemporary chiral form is given by :\mathcal=g(\partial^\mu\Sigma,\partial_\mu\Sigma)-V(\Sigma) where we have used a + − − − metric signature and the partial derivative is given by a section of the jet bundle of ''T''×''M'' and is the potential. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Model
The Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetism, electromagnetic, weak interaction, weak and strong interactions - excluding gravity) in the universe and classifying all known elementary particles. It was developed in stages throughout the latter half of the 20th century, through the work of many scientists worldwide, with the current formulation being finalized in the mid-1970s upon experimental confirmation of the existence of quarks. Since then, proof of the top quark (1995), the tau neutrino (2000), and the Higgs boson (2012) have added further credence to the Standard Model. In addition, the Standard Model has predicted various properties of weak neutral currents and the W and Z bosons with great accuracy. Although the Standard Model is believed to be theoretically self-consistent and has demonstrated huge successes in providing experimental predictions, it leaves some physics beyond the standard m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
