Institute for Advanced Study
Institute for Advanced Study
Institute For Advanced Study | Date: 2016-08-04
The invention relates to inhibitory nucleotide signal sequences or INS sequences in the genomes of lentiviruses. In particular the invention relates to the AGG motif present in all viral genomes. The AGG motif may have an inhibitory effect on a virus, for example by reducing the levels of, or maintaining low steady-state levels of, viral RNAs in host cells, and inducing and/or maintaining in viral latency. In one aspect, the invention provides vaccines that contain, or are produced from, viral nucleic acids in which the AGG sequences have been mutated. In another aspect, the invention provides methods and compositions for affecting the function of the AGG motif, and methods for identifying other INS sequences in viral genomes.
Witten E.,Institute for Advanced Study
Reviews of Modern Physics | Year: 2016
Symmetry-protected topological (SPT) phases of matter have been interpreted in terms of anomalies, and it has been expected that a similar picture should hold for SPT phases with fermions. Here a description is given in detail of what this picture means for phases of quantum matter that can be understood via band theory and free fermions. The main examples considered are time-reversal invariant topological insulators and superconductors in two or three space dimensions. Along the way, the precise meaning of the statement that in the bulk of a 3D topological insulator, the electromagnetic θ angle is equal to π, is clarified. © 2016 American Physical Society.
Henn J.M.,Institute for Advanced Study
Physical Review Letters | Year: 2013
Scattering amplitudes at loop level can be expressed in terms of Feynman integrals. The latter satisfy partial differential equations in the kinematical variables. We argue that a good choice of basis for (multi)loop integrals can lead to significant simplifications of the differential equations, and propose criteria for finding an optimal basis. This builds on experience obtained in supersymmetric field theories that can be applied successfully to generic quantum field theory integrals. It involves studying leading singularities and explicit integral representations. When the differential equations are cast into canonical form, their solution becomes elementary. The class of functions involved is easily identified, and the solution can be written down to any desired order in Ïμ within dimensional regularization. Results obtained in this way are particularly simple and compact. In this Letter, we outline the general ideas of the method and apply them to a two-loop example. © 2013 American Physical Society.
Gaiotto D.,Institute for Advanced Study
Journal of High Energy Physics | Year: 2012
We study the generalization of S-duality and Argyres-Seiberg duality for a large class of N = 2 superconformal gauge theories. We identify a family of strongly interacting SCFTs and use them as building blocks for generalized superconformal quiver gauge theories. This setup provides a detailed description of the "very strongly coupled" regions in the moduli space of more familiar gauge theories. As a byproduct, we provide a purely four dimensional construction of N = 2 theories defined by wrapping M5 branes over a Riemann surface. © SISSA 2012.
Jafferis D.L.,Institute for Advanced Study
Journal of High Energy Physics | Year: 2012
The three sphere partition function, Z, of three dimensional theories with four supercharges and an R-symmetry is computed using localization, resulting in a matrix integral over the Cartan of the gauge group. There is a family of couplings to the curved background, parameterized by a choice of R-charge, such that supersymmetry is preserved; Z is a function of those parameters. The magnitude of the result is shown to be extremized for the superconformal R-charge of the infrared conformal field theory, in the absence of mixing of the R-symmetry with accidental symmetries. This exactly determines the IR superconformal R-charge. © SISSA 2012.
Hook A.,Institute for Advanced Study
Physical Review Letters | Year: 2015
We present a new mechanism for solving the strong CP problem using a Z2 discrete symmetry and an anomalous U(1) symmetry. A Z2 symmetry is used so that two gauge groups have the same theta angle. An anomalous U(1) symmetry makes the difference between the two theta angles physical and the sum unphysical. Two models are presented where the anomalous symmetry manifests itself in the IR in different ways. In the first model, there are massless bifundamental quarks, a solution reminiscent of the massless up quark solution. In the IR of this model, the η′ boson relaxes the QCD theta angle to the difference between the two theta angles - in this case zero. In the second model, the anomalous U(1) symmetry is realized in the IR as a dynamically generated mass term that has exactly the phase needed to cancel the theta angle. Both of these models make the extremely concrete prediction that there exist new colored particles at the TeV scale. © 2015 American Physical Society.
Heckman J.J.,Institute for Advanced Study
Annual Review of Nuclear and Particle Science | Year: 2010
We review recent progress in realizing Grand Unified Theories (GUTs) in a strongly coupled formulation of type IIB string theory known as F-theory. This review's main emphasis is on the expected low-energy phenomenology of a minimal class of F-theory GUTs. We introduce the primary ingredients in such constructions, then present qualitative features of GUT models in this framework such as GUT breaking, doublet-triplet splitting, and proton decay. Next, we review proposals for realizing flavor hierarchies in the quark and lepton sectors. We discuss possible supersymmetry-breaking scenarios and their consequences for experiments, as well as geometrically minimal realizations of F-theory GUTs that incorporate most of these features. © 2010 by Annual Reviews. All rights reserved.
Pugatch R.,Institute for Advanced Study
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015
Bacterial self-replication is a complex process composed of many de novo synthesis steps catalyzed by a myriad of molecular processing units, e.g., the transcription-translation machinery, metabolic enzymes, and the replisome. Successful completion of all production tasks requires a schedule-a temporal assignment of each of the production tasks to its respective processing units that respects ordering and resource constraints. Most intracellular growth processes are well characterized. However, the manner in which they are coordinated under the control of a scheduling policy is not well understood. When fast replication is favored, a schedule that minimizes the completion time is desirable. However, if resources are scarce, it is typically computationally hard to find such a schedule, in the worst case. Here, we show that optimal scheduling naturally emerges in cellular self-replication. Optimal doubling time is obtained by maintaining a sufficiently large inventory of intermediate metabolites and processing units required for self-replication and additionally requiring that these processing units be "greedy," i.e., not idle if they can perform a production task. We calculate the distribution of doubling times of such optimally scheduled self-replicating factories, and find it has a universal form-log-Frechet, not sensitive to many microscopic details. Analyzing two recent datasets of Escherichia coli growing in a stationary medium, we find excellent agreement between the observed doubling-time distribution and the predicted universal distribution, suggesting E. coli is optimally scheduling its replication. Greedy scheduling appears as a simple generic route to optimal scheduling when speed is the optimization criterion. Other criteria such as efficiency require more elaborate scheduling policies and tighter regulation.
Bovy J.,Institute for Advanced Study
Astrophysical Journal, Supplement Series | Year: 2015
I describe the design, implementation, and usage of galpy, a python package for galactic-dynamics calculations. At its core, galpy consists of a general framework for representing galactic potentials both in python and in C (for accelerated computations); galpy functions, objects, and methods can generally take arbitrary combinations of these as arguments. Numerical orbit integration is supported with a variety of Runge-Kutta-type and symplectic integrators. For planar orbits, integration of the phase-space volume is also possible. galpy supports the calculation of action-angle coordinates and orbital frequencies for a given phase-space point for general spherical potentials, using state-of-the-art numerical approximations for axisymmetric potentials, and making use of a recent general approximation for any static potential. A number of different distribution functions (DFs) are also included in the current release; currently, these consist of two-dimensional axisymmetric and non-axisymmetric disk DFs, a three-dimensional disk DF, and a DF framework for tidal streams. I provide several examples to illustrate the use of the code. I present a simple model for the Milky Way's gravitational potential consistent with the latest observations. I also numerically calculate the Oort functions for different tracer populations of stars and compare them to a new analytical approximation. Additionally, I characterize the response of a kinematically warm disk to an elliptical m = 2 perturbation in detail. Overall, galpy consists of about 54,000 lines, including 23,000 lines of code in the module, 11,000 lines of test code, and about 20,000 lines of documentation. The test suite covers 99.6% of the code. galpy is available at http://github.com/jobovy/galpy with extensive documentation available at http://galpy.readthedocs.org/en/latest. © 2015. The American Astronomical Society. All rights reserved.
Agency: NSF | Branch: Continuing grant | Program: | Phase: Elem. Particle Physics/Theory | Award Amount: 360.00K | Year: 2016
This award funds the research activities of Professors Edward Witten and Peter Goddard and a group of postdoctoral fellows at the Institute for Advanced Study in Princeton.
The project is devoted to the study of elementary particle physics, including its connections to other areas of study ranging from astrophysics and cosmology to condensed matter physics and geometry. Current and planned work of the researchers supported by this grant covers a very wide range of topics, including the connections between gauge theory (the modern language of elementary particle physics), string theory (a speculative proposal for unifying the fundamental forces of nature), and geometry. These researchers will also study the possibilities for new models of particle physics that might be relevant at current and future particle accelerators; new methods of computing and studying the ways in which elementary particles scatter off each other; new experimental hints of the cosmic dark matter which makes up most of the matter in the universe; and more. Research in these areas thus advances the national interest by promoting the progress of science in one of its most fundamental directions: the discovery and understanding of new physical laws. The postdoctoral fellows supported by this project will also gain experience working at a high level on these exciting scientific problems, which have all attracted great interest nationally and internationally.
More technically, Edward Witten has been working most recently on applications of quantum field theory to boundary states of topological insulators and superconductors, and is also currently developing new interests in classical General Relativity, with a view toward implications for quantum theory. Peter Goddards focus is on new approaches to scattering amplitudes in gauge theory and gravity. The postdoctoral fellows supported by this project have a wide range of interests and work with each other on frontier topics in theoretical high-energy physics as well as with Professors Witten and Goddard and other local faculty.