COVID-19 information for PI Residents and Visitors
Wednesday, April 22, 2015
Time |
Event |
Location |
8:30 – 9:00am |
Registration |
Reception |
9:00 – 10:30am |
Edward Witten, Institute for Advanced Study |
Alice Room |
10:30 – 11:00am |
Coffee Break |
Bistro – 1^{st} Floor |
11:00 – 12:00pm |
Eric D’Hoker, University of California, Los Angeles |
Alice Room |
12:00 – 12:45pm |
Discussion 1 |
Alice Room |
12:45 – 2:15pm |
Lunch |
Reflecting Lounge |
2:15 – 3:15pm |
Katrin Becker, Texas A&M University |
Alice Room |
3:15 – 4:15pm |
Kevin Costello, Perimeter Institute |
Alice Room |
4:15 – 4:45pm |
Coffee Break |
Bistro – 1^{st} Floor |
4:45 – 5:45pm |
Laurent Freidel, Perimeter Institute |
Alice Room |
Thursday, April 23, 2015
Time |
Event |
Location |
9:00 – 10:30am |
Ashoke Sen, The Harish-Chandra Research Institute |
Alice Room |
10:30 – 11:00am |
Coffee Break |
Bistro – 1^{st} Floor |
11:00 – 12:00pm |
Arnab Rudra University of Cambridge |
Alice Room |
12:00 – 12:45pm |
Discussion 2 |
Alice Room |
12:45 – 2:15pm |
Lunch Break |
Bistro – 2^{nd} Floor |
2:15 – 3:15pm |
Michael Green, University of Cambridge |
Alice Room |
3:15 – 3:45pm |
Coffee Break |
Bistro – 1^{st} Floor |
3:45 – 4:45pm |
Rodolfo Russo, Queen Mary University of London |
Alice Room |
4:45 – 5:30pm |
Discussion 3 |
Alice Room |
5:30pm Onwards |
Banquet |
Bistro – 2^{nd} Floor |
Friday, April 24, 2015
Time |
Event |
Location |
9:00 – 10:30am |
Nathan Berkovits, Instituto de Física Teórica |
Alice Room |
10:30 – 11:00am |
Coffee Break |
Bistro – 1^{st} Floor |
11:00 – 12:00pm |
Andrei Mikhailov, Instituto de Física Teórica |
Alice Room |
12:00 – 12:45pm |
Discussion 4 |
Alice |
12:45 – 2:15pm |
Lunch |
Bistro – 2^{nd} Floor |
2:15 – 3:15pm |
Oliver Schlotterer, Albert Einstein Institute |
Alice Room |
3:15 – 3:45pm |
Coffee Break |
Bistro – 1^{st} Floor |
3:45 – 4:45pm |
Carlos Mafra, University of Cambridge |
Alice Room |
4:45 – 5:30pm |
Discussion 5 |
Alice Room |
Katrin Becker, Texas A&M University
M-theory and G2 manifolds
The uplift of classical solutions of M-theory to the quantum theory will be discussed.
Nathan Berkovits, Instituto de Física Teórica
Origin and Applications of the Pure Spinor Formalism
After reviewing its structure and discussing the twistor-like origin of the pure spinor formalism, I will speculate on possible applications for AdS_5xS^5 and M-theory
Eric D'Hoker, University of California, Los Angeles
Modular structure of Type IIB superstrings in the low energy expansion.
Laurent Freidel, Perimeter Institute
Metastring theory and Modular spacetime
In this talk I will review a recent reformulation of string theory which does not rely on an a priori space-time interpretation or a pre-assumption of locality and include form the onset stringy symmetries such as T-duality.
I will explain how this resulting theory, called metastring, leads to formulation where the string is chiral and the target is phase space instead of space-time. I will discuss metastring theory on a flat background and summarize a variety of technical and interpretational ideas. These include a discussion of moduli space of Lorentzian worldsheets, a generalization of the world sheet renormalisation group, a description of the geometry of phase space, a study of the symplectic structure and of closed and open boundary conditions, and the string spectrum and operator algebra.
What emerges from these studies is a new quantum notion of space-time that we call modular space-time. This new geometrical concept is fundamental quantum and modular. It is closely linked with T-duality and implements in a precise way a notion of relative locality.
Carlos Mafra, University of Cambridge
Explicit multiloop amplitude computations with the pure spinor formalism
In this talk I will show how to use the pure spinor formalism to compute multiloop string amplitudes, including their precise overall coefficients. I will also discuss the relevance of the recent four-point 3-loop and five-point 2-loop amplitudes for verifying some S-duality predictions.
Andrei Mikhailov, Instituto de Física Teórica
Notes on the Type II worldsheet sigma-model
Arnab Rudra, University of Cambridge
Mass renormalization and vacuum shift using Off-shell string theory
The conventional on-shell techniques of computing string theory amplitudes is not sufficient to compute mass renormalization of massive states and vacuum shift in string theory. The aim of this talk is to define a suitable off-shell continuation of Polyakov approach. Then this off-shell continuation will be used to compute mass-renormalization and perturbative vacuum shift in string theory.
Rodolfo Russo, Queen Mary University of London
Superstring amplitudes in the operator formalism
The operator formalism provides a constructive approach to superstring amplitudes that has two main virtues: it makes it possible to study explicitly all the degeneration limits and it is flexible enough to work in different setups. I will illustrate these two features in a concrete example: the twisted open string partition function at two loops, which describes the interactions between three D-branes in type II theories.
Oliver Schlotterer, Albert Einstein Institute
Multiloop SYM and supergravity amplitudes in pure spinor superspace
We present a string-inspired method to construct supersymmetric loop integrands for scattering amplitudes in ten-dimensional SYM and supergravity. The kinematic dependence is described in pure spinor superspace and determined from the BRST-symmetry of the underlying pure spinor superstring. We focus on five-point examples at one- and two-loop order which satisfy the BCJ duality between color and kinematics. Hence, the supergravity integrands follow straightforwardly from a double copy construction of the cubic diagrams in SYM. Preliminary examples and open questions at three-loops are mentioned.
Ashoke Sen, The Harish-Chandra Research Institute
1PI Effective Action for Superstring Perturbation Theory
In this talk I will show how to use the pure spinor formalism to compute multiloop string amplitudes, including their precise overall coefficients. I will also discuss the relevance of the recent four-point 3-loop and five-point 2-loop amplitudes for verifying some S-duality predictions.
We present a string-inspired method to construct supersymmetric loop integrands for scattering amplitudes in ten-dimensional SYM and supergravity. The kinematic dependence is described in pure spinor superspace and determined from the BRST-symmetry of the underlying pure spinor superstring. We focus on five-point examples at one- and two-loop order which satisfy the BCJ duality between color and kinematics. Hence, the supergravity integrands follow straightforwardly from a double copy construction of the cubic diagrams in SYM.
After reviewing its structure and discussing the twistor-like origin of the pure spinor formalism, I will speculate on possible applications for AdS_5xS^5 and M-theory
The operator formalism provides a constructive approach to superstring amplitudes that has two main virtues: it makes it possible to study explicitly all the degeneration limits and it is flexible enough to work in different setups. I will illustrate these two features in a concrete example: the twisted open string partition function at two loops, which describes the interactions between three D-branes in type II theories.
The conventional on-shell techniques of computing string theory amplitudes is not sufficient to compute mass renormalization of massive states and vacuum shift in string theory. The aim of this talk is to define a suitable off-shell continuation of Polyakov approach. Then this off-shell continuation will be used to compute mass-renormalization and perturbative vacuum shift in string theory.
Scientific Organizers:
Davide Gaiotto, Perimeter Institute
Jaume Gomis, Perimeter institute
Ashoke Sen, The Harish-Chandra Research Institute
Edward Witten, Institute for Advanced Study