Rachel A. Rosen | |
---|---|
Born | 31 August 1983 |
Education | |
Scientific career | |
Fields | Theoretical physics |
Doctoral advisor | Gregory Gabadadze |
Rachel A. Rosen is a physicist and associate professor of Theoretical Physics at Carnegie Mellon University. [1] [2] Her research involves quantum field theory, cosmology, astrophysics and massive gravity. In particular, she has investigated the problem of the inconsistencies known as "ghosts," and how to formulate models of massive gravity that avoid them.
Rosen received her undergraduate degree in mathematics and physics from Brown University. At New York University, she studied the Bullet Cluster with Glennys Farrar and helium-core white dwarfs with Gregory Gabadadze. She received her PhD from that institution in 2009. [3] [4] In 2013, she received a Blavatnik Award for a Young Scientist for work on massive gravity. [5] She is a visiting fellow at the Perimeter Institute for Theoretical Physics. [6]
In July 2017, the Simons Foundation announced that Gabadadze, Rosen and Claudia de Rham would lead a "Cosmology Beyond Einstein's Gravity" research effort as part of the Foundation's new cosmology initiative. [7]
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.
Induced gravity is an idea in quantum gravity that spacetime curvature and its dynamics emerge as a mean field approximation of underlying microscopic degrees of freedom, similar to the fluid mechanics approximation of Bose–Einstein condensates. The concept was originally proposed by Andrei Sakharov in 1967.
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, massive gravity is a theory of gravity that modifies general relativity by endowing the graviton with a nonzero mass. In the classical theory, this means that gravitational waves obey a massive wave equation and hence travel at speeds below the speed of light.
The DGP model is a model of gravity proposed by Gia Dvali, Gregory Gabadadze, and Massimo Porrati in 2000. The model is popular among some model builders, but has resisted being embedded into string theory.
Loop quantum cosmology (LQC) is a finite, symmetry-reduced model of loop quantum gravity (LQG) that predicts a "quantum bridge" between contracting and expanding cosmological branches.
Igor R. Klebanov is an American theoretical physicist. Since 1989, he has been a faculty member at Princeton University where he is currently a Eugene Higgins Professor of Physics and the director of the Princeton Center for Theoretical Science. In 2016, he was elected to the National Academy of Sciences. Since 2022, he is the director of the Simons Collaboration on Confinement and QCD Strings.
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.
Gregory Gabadadze is a Georgian theoretical physicist specializing in the field of gravity. He holds the position of Professor of Physics at New York University, where he also serves as the Dean for Science. In his previous roles at NYU, Gabadadze was the Chair of the Department of Physics and the Director of the Center for Cosmology and Particle Physics.
The Bousso bound captures a fundamental relation between quantum information and the geometry of space and time. It appears to be an imprint of a unified theory that combines quantum mechanics with Einstein's general relativity. The study of black hole thermodynamics and the information paradox led to the idea of the holographic principle: the entropy of matter and radiation in a spatial region cannot exceed the Bekenstein–Hawking entropy of the boundary of the region, which is proportional to the boundary area. However, this "spacelike" entropy bound fails in cosmology; for example, it does not hold true in our universe.
Bimetric gravity or bigravity refers to two different classes of theories. The first class of theories relies on modified mathematical theories of gravity in which two metric tensors are used instead of one. The second metric may be introduced at high energies, with the implication that the speed of light could be energy-dependent, enabling models with a variable speed of light.
In theoretical physics, the dual graviton is a hypothetical elementary particle that is a dual of the graviton under electric-magnetic duality, as an S-duality, predicted by some formulations of supergravity in eleven dimensions.
Veronika E. Hubeny is an American physicist and academic who specialises in string theory and quantum gravity. Since 2015, she has been a professor in the Department of Physics of University of California, Davis. Previously, Hubeny was Professor of Physics at Durham University, where she had worked from 2005 to 2015. From January to April 2014, she was a member of the Institute for Advanced Study in Princeton, New Jersey. In 2019, she was selected as a fellow of the International Society on General Relativity and Gravitation.
Claudia de Rham is a Swiss theoretical physicist working at the interface of gravity, cosmology and particle physics. She is based at Imperial College London. She was one of the UK finalists in the Physical Sciences and Engineering category of the Blavatnik Award for Young Scientists in 2018 for revitalizing the theory of massive gravity, and won the award in 2020.
Thomas Hertog is a Belgian cosmologist at KU Leuven university and was a key collaborator of Professor Stephen Hawking.
Douglas Stanford is an American theoretical physicist. He is an associate professor of physics at Stanford Institute for Theoretical Physics of Stanford University. His research interests include quantum gravity, quantum field theory and string theory. Stanford was awarded the 2018 New Horizons in Physics Prize by Fundamental Physics Prize Foundation for his work on improving the understanding of quantum mechanics of black holes via chaos theory.
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.
Melanie Becker was a physicist known for her research into string theory. She was a tenured professor of physics at Texas A&M University upon her death in 2020.
In theoretical physics, double field theory refers to formalisms that capture the T-duality property of string theory as a manifest symmetry of a field theory.