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, supergravity is a modern field theory that combines the principles of supersymmetry and general relativity; this is in contrast to non-gravitational supersymmetric theories such as the Minimal Supersymmetric Standard Model. Supergravity is the gauge theory of local supersymmetry. Since the supersymmetry (SUSY) generators form together with the Poincaré algebra a superalgebra, called the super-Poincaré algebra, supersymmetry as a gauge theory makes gravity arise in a natural way.
In supergravity theories combining general relativity and supersymmetry, the gravitino is the gauge fermion supersymmetric partner of the hypothesized graviton. It has been suggested as a candidate for dark matter.
Nathan "Nati" Seiberg is an Israeli American theoretical physicist who works on quantum field theory and string theory. He is currently a professor at the Institute for Advanced Study in Princeton, New Jersey, United States.
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.
Pran Nath is a theoretical physicist working at Northeastern University, with research focus in elementary particle physics. He holds a Matthews Distinguished University Professor chair.
Savas Dimopoulos is a particle physicist at Stanford University. He worked at CERN from 1994 to 1997. Dimopoulos is well known for his work on constructing theories beyond the Standard Model.
The history of string theory spans several decades of intense research including two superstring revolutions. Through the combined efforts of many researchers, string theory has developed into a broad and varied subject with connections to quantum gravity, particle and condensed matter physics, cosmology, and pure mathematics.
John (Jean) Iliopoulos is a Greek physicist. He is the first person to present the Standard Model of particle physics in a single report. He is best known for his prediction of the charm quark with Sheldon Glashow and Luciano Maiani. Iliopoulos is also known for demonstrating the cancellation of anomalies in the Standard model. He is further known for the Fayet-Iliopoulos D-term formula, which was introduced in 1974. He is currently an honorary member of Laboratory of theoretical physics of École Normale Supérieure, Paris.
In theoretical particle physics, maximally helicity violating amplitudes (MHV) are amplitudes with massless external gauge bosons, where gauge bosons have a particular helicity and the other two have the opposite helicity. These amplitudes are called MHV amplitudes, because at tree level, they violate helicity conservation to the maximum extent possible. The tree amplitudes in which all gauge bosons have the same helicity or all but one have the same helicity vanish.
Gordon Leon Kane is Victor Weisskopf Distinguished University Professor at the University of Michigan and director emeritus at the Leinweber Center for Theoretical Physics (LCTP), a leading center for the advancement of theoretical physics. He was director of the LCTP from 2005 to 2011 and Victor Weisskopf Collegiate Professor of Physics from 2002 - 2011. He received the Lilienfeld Prize from the American Physical Society in 2012, and the J. J. Sakurai Prize for Theoretical Particle Physics in 2017.
Riccardo Barbieri is an Italian theoretical physicist and a professor at the Scuola Normale Superiore di Pisa. He has written more than two hundred research papers in the field of theoretical elementary particle physics, and has been particularly influential in physics beyond the Standard Model.
Stuart Samuel is a theoretical physicist known for his work on the speed of gravity and for his work with Alan Kostelecký on spontaneous Lorentz violation in string theory, now called the Bumblebee model. He also made significant contributions in field theory and particle physics.
Augusto Sagnotti is an Italian theoretical physicist at Scuola Normale.
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.
Paul Stephen Aspinwall is a British theoretical physicist and mathematician, who works on string theory and also algebraic geometry.
Michael Dine is an American theoretical physicist, specializing in elementary particle physics, supersymmetry, string theory, and physics beyond the Standard Model.
Costas Christou Kounnas was a Cypriot theoretical physicist, known for his research on string theory, supersymmetry, supergravity, GUTs, and quantum chromodynamics.
Ignatios Antoniadis is a Greek theoretical physicist, specializing in string theory and particle physics.
