Grand Unified Theory (GUT) is any model in particle physics that merges the electromagnetic, weak, and strong forces into a single force at high energies. Although this unified force has not been directly observed, many GUT models theorize its existence. If the unification of these three interactions is possible, it raises the possibility that there was a grand unification epoch in the very early universe in which these three fundamental interactions were not yet distinct.
M-theory is a theory in physics that unifies all consistent versions of superstring theory. Edward Witten first conjectured the existence of such a theory at a string theory conference at the University of Southern California in 1995. Witten's announcement initiated a flurry of research activity known as the second superstring revolution. Prior to Witten's announcement, string theorists had identified five versions of superstring theory. Although these theories initially appeared to be very different, work by many physicists showed that the theories were related in intricate and nontrivial ways. Physicists found that apparently distinct theories could be unified by mathematical transformations called S-duality and T-duality. Witten's conjecture was based in part on the existence of these dualities and in part on the relationship of the string theories to a field theory called eleven-dimensional supergravity.
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. String theory describes how these strings propagate through space and interact with each other. On distance scales larger than the string scale, a string looks just like an ordinary particle, with its mass, charge, and other properties determined by the vibrational state of the string. In string theory, one of the many vibrational states of the string corresponds to the graviton, a quantum mechanical particle that carries the gravitational force. Thus, string theory is a theory of quantum gravity.
A theory of everything (TOE), final theory, ultimate theory, unified field theory or master theory is a hypothetical, singular, all-encompassing, coherent theoretical framework of physics that fully explains and links together all aspects of the universe. Finding a theory of everything is one of the major unsolved problems in physics.
Supersymmetry is a theoretical framework in physics that suggests the existence of a symmetry between particles with integer spin (bosons) and particles with half-integer spin (fermions). It proposes that for every known particle, there exists a partner particle with different spin properties. This symmetry has not been observed in nature. If confirmed, it could help explain certain phenomena, such as the nature of dark matter and the hierarchy problem in particle physics.
Cosmic strings are hypothetical 1-dimensional topological defects which may have formed during a symmetry-breaking phase transition in the early universe when the topology of the vacuum manifold associated to this symmetry breaking was not simply connected. Their existence was first contemplated by the theoretical physicist Tom Kibble in the 1970s.
Brian Randolph Greene is an American theoretical physicist and mathematician. Greene was a physics professor at Cornell University from 1990–1995, and has been a professor at Columbia University since 1996 and chairman of the World Science Festival since co-founding it in 2008. Greene has worked on mirror symmetry, relating two different Calabi–Yau manifolds. He also described the flop transition, a mild form of topology change, showing that topology in string theory can change at the conifold point.
Erik Peter Verlinde is a Dutch theoretical physicist and string theorist. He is the identical twin brother of physicist Herman Verlinde. The Verlinde formula, which is important in conformal field theory and topological field theory, is named after him. His research deals with string theory, gravity, black holes and cosmology. Currently, he works at the Institute for Theoretical Physics at the University of Amsterdam.
Dimitri V. Nanopoulos is a Greek physicist. He is one of the most regularly cited researchers in the world, cited more than 48,500 times across a number of separate branches of science.
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.
Jonathan Richard Ellis is a British theoretical physicist who is currently Clerk Maxwell Professor of Theoretical Physics at King's College London.
Burt Ovrut is an American theoretical physicist best known for his work on heterotic string theory. He is currently Professor of Theoretical High Energy Physics at the University of Pennsylvania.
Emil John Martinec is an American string theorist, a physics professor at the Enrico Fermi Institute at the University of Chicago, and director of the Kadanoff Center for Theoretical Physics. He was part of a group at Princeton University that developed heterotic string theory in 1985.
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.
Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings.
Anzhong Wang is a theoretical physicist, specialized in gravitation, cosmology and astroparticle physics. He holds a position on the Physics faculty of Baylor University. Currently he is working on cosmology in string/M theory and the Hořava–Lifshitz gravity.
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.
Ana Achúcarro Jiménez is a Spanish researcher, academic, and professor of particle astrophysics and quantum field theory at the University of Leiden in Leiden, Netherlands. Her research considers the early universe, supergravity, black holes and solitons.
Qaisar Shafi is a Pakistani-American theoretical physicist and the Inaugural Bartol Research Institute Professor of Physics at the University of Delaware.
