Richard Bond, Ph.D. University of Toronto
Claudia de Rham, Ph.D. Imperial College London
Raphael Flauger, Ph.D. University of California, San Diego
Gregory Gabadadze, Ph.D. New York University
Anna Ijjas, Ph.D. Harvard University
Liam McAllister, Ph.D. Cornell University
Massimo Porrati, Ph.D. New York University
Rachel Rosen, Ph.D. Columbia University
Eva Silverstein, Ph.D. Stanford University
Paul Steinhardt, Ph.D. Princeton University
Matias Zaldarriaga, Ph.D. Institute for Advanced Study
|Research in Modern Inflationary Cosmology||Cosmology Beyond Einstein's Theory||Cosmological Bounces and Bouncing Cosmologies|
Porrati, Massimo & Gabadadze, Gregory
New York University
University of Toronto
|de Rham, Claudia
Imperial College London
University of California, San Diego
Institute for Advanced Study
The Origins of the Universe project is designed to advance our understanding of the universe by stimulating theoretical research into mechanisms of cosmogenesis.
The Simons Foundation effort will develop testable predictions about string theory, quantum gravity and a cosmological ‘big bounce.’ To do so, the foundation has assembled an international group of theoretical physicists to tackle one of the biggest unsolved mysteries in science: what exactly went down at the dawn of the universe around 13.8 billion years ago.
Einstein’s gravity correctly describes astrophysical and cosmological phenomena at hugely diverse scales and is one of the most successful theories of all times. Yet experiment and observation have raised questions that might require theories beyond Einstein’s, including the cosmological constant problem, the lack of fundamental understanding of the accelerated expansion of the universe and the enigma of the beginning of the universe. The Cosmology Beyond Einstein’s Theory group will explore these issues.
The Research in Modern Inflationary Cosmology group will expand our understanding of inflationary dynamics, providing new insights into the density perturbations seeding structure in the universe as well as into the observational constraints on the theory. A key issue will be non-Gaussianity in the cosmic microwave background fluctuations. The group will develop the underlying theory, with control of quantum gravity effects, including typical string theoretic solutions with classical potential energies and many axion fields.
The Cosmological Bounces and Bouncing Cosmologies group will address the major open question of whether the universe started with a bang or a cosmological bounce (cyclic cosmology), a smooth transition from a preceding period of contraction to the current period of expansion. Cyclic cosmologies have advantageous properties: dark energy is a predicted feature and the vacuum state today must be metastable (though long lived), a possibility which relates to recent measurements of the Higgs and top-quark masses at the Large Hadron Collider, but until recently, attempts to construct cyclic solutions have led to severe theoretical problems. In the past year, however, several independent approaches have been introduced that seem to overcome these historic roadblocks, and these breakthroughs motivate the research of this group.
Paul Steinhardt‘s research spans problems in particle physics, astrophysics, cosmology and condensed matter physics. He is one of the original architects of the inflationary model, an important modification of the standard big bang picture that explains the large-scale homogeneity, geometry and structure of the universe. He was among the first to show that quantum fluctuations combined with inflation can generate a nearly scale-invariant spectrum of density variations, and, then, extending these ideas, he was the first to demonstrate that inflation can be eternal, the result of which is the multiverse. He introduced the concept of ‘quintessence,’ a dynamical form of dark energy that may account for the recently discovered cosmic acceleration. He has also introduced novel models for dark matter, including self-interacting dark matter (SIDM).
Eva Silverstein is a physicist, cosmologist and string theorist. She is best known for her work on early universe cosmology, developing the structure of inflation and its range of signatures, as well as extensive contributions to string theory and gravitational physics. Her early work included control of tachyon condensation in string theory and resulting resolution of some space-time singularities (with Adams, Polchinski and others). Other significant research contributions include the construction of the first models of dark energy in string theory, some basic extensions of the AdS/CFT correspondence to more realistic field theories (with Kachru), as well as the discovery of a predictive, new mechanism for cosmic inflation involving D-brane dynamics (with Tong and Alishahiha) which helped motivate more systematic analyses of primordial non-Gaussianity.
Massimo Porrati is a professor of physics, and a member of the Center for Cosmology and Particle Physics, at New York University. His major research interests are string theory, supersymmetry and supergravity, nonperturbative aspects of strings and quantum field theory, and cosmology. Among others, Porrati is known for his work on the large-distance modification of gravity and its application to the cosmological constant problem. With Gia Dvali and Gregory Gabadadze he co-pioneered and advanced this direction by proposing a generally covariant model of infrared modification of gravity (the so-called DGP model), and studying many novel and subtle features of this class of models.