String field theory (SFT) is a formalism in string theory in which the dynamics of relativistic strings is reformulated in the language of quantum field theory. This is accomplished at the level of perturbation theory by finding a collection of vertices for joining and splitting strings, as well as string propagators, that give a Feynman diagram-like expansion for string scattering amplitudes. In most string field theories, this expansion is encoded by a classical action found by second-quantizing the free string and adding interaction terms. As is usually the case in second quantization, a classical field configuration of the second-quantized theory is given by a wave function in the original theory. In the case of string field theory, this implies that a classical configuration, usually called the string field, is given by an element of the free string Fock space.
In theoretical physics, twistor theory was proposed by Roger Penrose in 1967 as a possible path to quantum gravity and has evolved into a widely studied branch of theoretical and mathematical physics. Penrose's idea was that twistor space should be the basic arena for physics from which space-time itself should emerge. It has led to powerful mathematical tools that have applications to differential and integral geometry, nonlinear differential equations and representation theory, and in physics to general relativity, quantum field theory, and the theory of scattering amplitudes. Twistor theory arose in the context of the rapidly expanding mathematical developments in Einstein's theory of general relativity in the late 1950s and in the 1960s and carries a number of influences from that period. In particular, Roger Penrose has credited Ivor Robinson as an important early influence in the development of twistor theory, through his construction of so-called Robinson congruences.
In theoretical physics, S-duality is an equivalence of two physical theories, which may be either quantum field theories or string theories. S-duality is useful for doing calculations in theoretical physics because it relates a theory in which calculations are difficult to a theory in which they are easier.
In mathematics and string theory, a conifold is a generalization of a manifold. Unlike manifolds, conifolds can contain conical singularities, i.e. points whose neighbourhoods look like cones over a certain base. In physics, in particular in flux compactifications of string theory, the base is usually a five-dimensional real manifold, since the typically considered conifolds are complex 3-dimensional spaces.
Montonen–Olive duality or electric–magnetic duality is the oldest known example of strong–weak duality or S-duality according to current terminology. It generalizes the electro-magnetic symmetry of Maxwell's equations by stating that magnetic monopoles, which are usually viewed as emergent quasiparticles that are "composite", can in fact be viewed as "elementary" quantized particles with electrons playing the reverse role of "composite" topological solitons; the viewpoints are equivalent and the situation dependent on the duality. It was later proven to hold true when dealing with a N = 4 supersymmetric Yang–Mills theory. It is named after Finnish physicist Claus Montonen and British physicist David Olive after they proposed the idea in their academic paper Magnetic monopoles as gauge particles? where they state:
There should be two "dual equivalent" field formulations of the same theory in which electric (Noether) and magnetic (topological) quantum numbers exchange roles.
In theoretical physics, a primary field, also called a primary operator, or simply a primary, is a local operator in a conformal field theory which is annihilated by the part of the conformal algebra consisting of the lowering generators. From the representation theory point of view, a primary is the lowest dimension operator in a given representation of the conformal algebra. All other operators in a representation are called descendants; they can be obtained by acting on the primary with the raising generators.
Erick J. Weinberg is a theoretical physicist and professor of physics at Columbia University.
In theoretical physics, a logarithmic conformal field theory is a conformal field theory in which the correlators of the basic fields are allowed to be logarithmic at short distance, instead of being powers of the fields' distance. Equivalently, the dilation operator is not diagonalizable.
In theoretical particle physics, the non-commutative Standard Model, is a model based on noncommutative geometry that unifies a modified form of general relativity with the Standard Model.
Renata Elizaveta Kallosh is a Russian-American theoretical physicist. She is a professor of physics at Stanford University, working there on supergravity, string theory and inflationary cosmology.
Warren Siegel is a theoretical physicist specializing in supersymmetric quantum field theory and string theory. He was a professor at the C. N. Yang Institute for Theoretical Physics at Stony Brook University. He retired in Fall of 2022.
In mathematics, a Verlinde algebra is a finite-dimensional associative algebra introduced by Erik Verlinde, with a basis of elements φλ corresponding to primary fields of a rational two-dimensional conformal field theory, whose structure constants Nν
λμ describe fusion of primary fields.
Augusto Sagnotti is an Italian theoretical physicist at Scuola Normale.
Sheldon H. Katz is an American mathematician, specializing in algebraic geometry and its applications to string theory.
Peter Christopher West, born on 4 December 1951, is a British theoretical physicist at King's College, London and a fellow of the Royal Society.
Claus Kalevi Montonen is a Finnish theoretical physicist, most known for his work with British physicist David Olive in proposing the Montonen–Olive duality.
Olaf Lechtenfeld is a German mathematical physicist, academic and researcher. He is a full professor at the Institute of Theoretical Physics at Leibniz University, where he founded the Riemann Center for Geometry and Physics.
Krzysztof Gawędzki was a Polish mathematical physicist, a graduate of the University of Warsaw and professor at the École normale supérieure de Lyon. He was primarily known for his research on quantum field theory and statistical physics. In 2022, he shared the Dannie Heineman Prize for Mathematical Physics with Antti Kupiainen.
Hermann Nicolai is a German theoretical physicist and director emeritus at the Max Planck Institute for Gravitational Physics in Potsdam-Golm.
Pietro G. Frè is an Italian theoretical physicist and an emeritus full professor of the University of Turin.
