Quantum Fields and Strings

Displaying 433 - 444 of 725

All one-loop amplitudes in N=6 Chern-Simons matter theories

Congkao Wen
Queen Mary University of London
December 18, 2012

PIRSA:12120005
Quantum Fields and Strings
(0,2) Gauge Dynamics and Flux Compactifications

Callum Quigley
Kirkland & Ellis
December 11, 2012

PIRSA:12120006
Quantum Fields and Strings
Unitarity, black hole microstates and how Alices fuzzes but may not even know it

Andrea Puhm
University of Amsterdam
December 06, 2012

PIRSA:12120029
Quantum Fields and Strings
The Spectrum of Strings on Warped AdS3

Wei Song
Harvard University
December 05, 2012

PIRSA:12120027
Quantum Fields and Strings
Moduli Stabilization and Holographic RG
December 04, 2012

PIRSA:12120002
Quantum Fields and Strings
Chern-Simons Contact Terms

Thomas Dumitrescu
University of California, Los Angeles
November 28, 2012

PIRSA:12110094
Quantum Fields and Strings
Bootstrapping CFTs with the Extremal Functional Method

Miguel Paulos
École Normale Supérieure - PSL
November 27, 2012

PIRSA:12110049
Quantum Fields and Strings
3 point functions in the AdS4/CFT3 correspondence

Agnese Bissi
The Abdus Salam International Centre for Theoretical Physics (ICTP)
November 20, 2012

PIRSA:12110053
Quantum Fields and Strings
Anomaly-induced transport and thermodynamics

Kristan Jensen
University of Victoria
November 13, 2012

PIRSA:12110047
Quantum Fields and Strings
Holomorphic Blocks in 3d

Tudor Dimofte
University of Edinburgh
November 06, 2012

PIRSA:12110056
Quantum Fields and Strings
From Effective Strings to the Simplest theory of Quantum Gravity
October 23, 2012

PIRSA:12100040
Quantum Fields and Strings
Constraining RG flow in three-dimensional field theory

Benjamin Safdi
Massachusetts Institute of Technology (MIT)
October 16, 2012

PIRSA:12100054
Quantum Fields and Strings

All one-loop amplitudes in N=6 Chern-Simons matter theories

Congkao Wen
Queen Mary University of London
December 18, 2012

PIRSA:12120005
Quantum Fields and Strings
In this talk we will present results on all one-loop scattering amplitudes in N=6 Chern-Simons matter theories. Especially we will discuss connection between certain triple-cut diagrams and tree-level recursive diagrams, and a general formula capturing the multi-particle factorization of arbitrary one-loop amplitudes in the theories is obtained from this connection. Furthermore a recursion relation for the supercoefficients of one-loop amplitudes will be derived, which leads the solution for all one-loop amplitudes.
(0,2) Gauge Dynamics and Flux Compactifications

Callum Quigley
Kirkland & Ellis
December 11, 2012

PIRSA:12120006
Quantum Fields and Strings
Two-dimensional gauge theories with (0,2) supersymmetry admit a much broader, and more interesting, class of solutions than their better studied (2,2) counterparts. In this talk, we will explore some of the possibilities that are offered by this additional freedom. The moduli spaces we find can be interpreted as the target spaces for heterotic strings moving in backgrounds with non-trivial H-flux. A remarkable relationship between (0,2) gauge anomalies and H-flux will emerge.
Unitarity, black hole microstates and how Alices fuzzes but may not even know it

Andrea Puhm
University of Amsterdam
December 06, 2012

PIRSA:12120029
Quantum Fields and Strings
The information paradox and the infall problem have been long-standing puzzles in the understanding of black holes. The idea of free infall is in considerable tension with unitarity of the evaporation process and recent developements have made this tension sharp. In the first part of my talk I will address the information question and argue that unitarty requires every quantum of radiation leaving the black hole to carry information about the initial state. Unitary evaporation is thus inconsistent with an information-free horizon at every step of the evaporation process and this extends the recent firewall result. This immediately raises the question of What is the required horizon-scale structure? I will show an explicit construction of near-extremal black hole microstates which put flesh and branes on the fuzzball proposal and may realize firewalls in string theory. In the second part I will address the question of What happens to an observer falling into a fuzzball? I will argue that the answer is dependent on the energy scale of the infalling observer.
The Spectrum of Strings on Warped AdS3

Wei Song
Harvard University
December 05, 2012

PIRSA:12120027
Quantum Fields and Strings
Warped AdS3 has isometry SL(2,R) x U(1). It is closed related to Kerr/CFT, non local dipole theories and AdS/CMT. In this talk I will derive the spectrum of string theory on Warped AdS3. This is possible because the worldsheet theory can be mapped to the worldsheet on AdS3 by a nonlocal field redefinition.
Moduli Stabilization and Holographic RG
December 04, 2012

PIRSA:12120002
Quantum Fields and Strings
In this talk, I will relate moduli stabilization in AdS or de Sitter space to basic properties of the Wilsonian action in the holographic dual theory living on dS (of one lower dimension): the single-trace terms in the action have vanishing beta functions, and higher-trace couplings are determined purely from lower-trace ones (a property we refer to as the iterative structure of RG). In the dS case, this encodes the maximal symmetry of the bulk spacetime in a quantity which is accessible within a single observer's patch.
Chern-Simons Contact Terms

Thomas Dumitrescu
University of California, Los Angeles
November 28, 2012

PIRSA:12110094
Quantum Fields and Strings
Chern-Simons contact terms constitute new observables in three-dimensional quantum field theory. In N=2 supersymmetric theories with an R-symmetry, they lead to a superconformal anomaly. This understanding clarifies several puzzles surrounding the S3 partition function of these theories. In particular, it leads to a proof of the F-maximization principle. Chern-Simons contact terms can be computed exactly using localization and lead to new tests of proposed dualities.
Bootstrapping CFTs with the Extremal Functional Method

Miguel Paulos
École Normale Supérieure - PSL
November 27, 2012

PIRSA:12110049
Quantum Fields and Strings
The existence of a positive linear functional acting on the space of (differences between) conformal blocks has been shown to rule out regions in the parameter space of conformal field theories (CFTs). We argue that at the boundary of the allowed region the extremal functional contains, in principle, enough information to determine the dimensions and OPE coefficients of an infinite number of operators appearing in the correlator under analysis. Based on this idea we develop the Extremal Functional Method (EFM), a numerical procedure for deriving the spectrum and OPE coefficients of CFTs lying on the boundary (of solution space). We test the EFM by using it to rederive the low lying spectrum and OPE coefficients of the 2d Ising model based solely on the dimension of a single scalar quasi-primary -- no Virasoro algebra required. Our work serves as a benchmark for applications to more interesting, less known CFTs in the near future, such as the 3d Ising model.
3 point functions in the AdS4/CFT3 correspondence

Agnese Bissi
The Abdus Salam International Centre for Theoretical Physics (ICTP)
November 20, 2012

PIRSA:12110053
Quantum Fields and Strings
I will present recent developments in the computation of three point functions in the AdS4/CFT3 correspondence. More specifically I will consider two different computations for three point functions of operators belonging to the SU(2)XSU(2) sector of ABJM. I will discuss first the generalization of the determinant representation, found by Foda for the three-point functions of the SU(2) sector of N = 4 SYM, to the ABJM theory and secondly semiclassical computations in the case where two operators are heavy and one is light and BPS, comparing the results obtained in the gauge theory side using a coherent state description of the heavy operators with its string theory counterpart calculated holographically.
Anomaly-induced transport and thermodynamics

Kristan Jensen
University of Victoria
November 13, 2012

PIRSA:12110047
Quantum Fields and Strings
I will discuss recent progress in the study of anomaly-induced transport, focusing on the chiral vortical effect in 3+1 dimensions. Most of my discussion will be framed in light of a larger story, namely progress in making exact statements about finite-temperature quantum field theory, for which the chiral magnetic and vortical effects are instructive prototypes.
Holomorphic Blocks in 3d

Tudor Dimofte
University of Edinburgh
November 06, 2012

PIRSA:12110056
Quantum Fields and Strings
Recently techniques have been developed to compute the partition functions of 3d theories with N=2 supersymmetry on curved, compact spaces, in particular S^3 and S^2xS^1 (the latter giving a supersymmetric index). I will discuss how both of these partition functions can be decomposed as products of more fundamental, universal "holomorphic blocks." For 3d gauge theories arising from (auxiliary) 3-manifolds M, these holomorphic blocks are specific Chern-Simons partition functions on M.
From Effective Strings to the Simplest theory of Quantum Gravity
October 23, 2012

PIRSA:12100040
Quantum Fields and Strings
String-like objects arise in many quantum field theories. Well known examples include flux tubes in QCD and cosmic strings. To a first approximation, their dynamics is governed by the Nambu-Goto action, but for QCD flux tubes numerical calculations of the energy levels of these objects have become so accurate that a systematic understanding of corrections to this simple description is desirable. In the first part of my talk, I discuss an effective field theory describing long relativistic strings. The construction parallels that of the chiral Lagrangian in that it is based on the pattern of symmetry breaking. To compare with previous works, I will present the results of the calculation of the S-matrix describing the scattering of excitations on the string worldsheet. In the second part of my talk, I will discuss critical strings from the same point of view and show that the worldsheet S-matrix in this case is non-trivial but can be calculated exactly. I will show that it encodes the familiar square-root formula for the energy levels of the string, the Hagedorn behavior of strings, and argue that the theory on the string worldsheet behaves like a 1+1 dimensional theory of quantum gravity rather than a field theory. If time permits, I will return to the task of computing the energy levels of flux-tubes using lessons learned from the second part of my talk.
Constraining RG flow in three-dimensional field theory

Benjamin Safdi
Massachusetts Institute of Technology (MIT)
October 16, 2012

PIRSA:12100054
Quantum Fields and Strings
The entanglement entropy S(R) across a circle of radius R has been invoked recently in deriving general constraints on renormalization group flow in three-dimensional field theory. At conformal fixed points, the negative of the finite part of the entanglement entropy, which is called F, is equal to the free energy on the round three-sphere. The F-theorem states that F decreases under RG flow. Along the RG flow it has recently been shown that the renormalized entanglement entropy {\cal F}(R) = -S(R) + R S'(R), which is equal to F at the fixed points, is a monotonically decreasing function. I will review various three-dimensional field theories where we can calculate F on the three-sphere and compute its change under RG flow, including free field theories, perturbative fixed points, large N field theories with double trace deformations, gauge theories with large numbers of flavors, and supersymmetric theories with at least {\cal N} = 2 supersymmetry. I will also present calculations of the renormalized entanglement entropy along the RG flow in free massive field theory and in holographic examples.

Title	Speaker(s)	Date	Talk Type	Info
All one-loop amplitudes in N=6 Chern-Simons matter theories	Congkao Wen	2012-12-18	Scientific Series	View details
(0,2) Gauge Dynamics and Flux Compactifications	Callum Quigley	2012-12-11	Scientific Series	View details
Unitarity, black hole microstates and how Alices fuzzes but may not even know it	Andrea Puhm	2012-12-06	Scientific Series	View details
The Spectrum of Strings on Warped AdS3	Wei Song	2012-12-05	Scientific Series	View details
Moduli Stabilization and Holographic RG		2012-12-04	Scientific Series	View details
Chern-Simons Contact Terms	Thomas Dumitrescu	2012-11-28	Scientific Series	View details
Bootstrapping CFTs with the Extremal Functional Method	Miguel Paulos	2012-11-27	Scientific Series	View details
3 point functions in the AdS4/CFT3 correspondence	Agnese Bissi	2012-11-20	Scientific Series	View details
Anomaly-induced transport and thermodynamics	Kristan Jensen	2012-11-13	Scientific Series	View details
Holomorphic Blocks in 3d	Tudor Dimofte	2012-11-06	Scientific Series	View details
From Effective Strings to the Simplest theory of Quantum Gravity		2012-10-23	Scientific Series	View details
Constraining RG flow in three-dimensional field theory	Benjamin Safdi	2012-10-16	Scientific Series	View details

Quantum Fields and Strings

Format results