Quantum Fields and Strings

Displaying 445 - 456 of 732

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
AdS(3)/CFT(2) correspondence and integrability

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 09, 2012

PIRSA:12100062
Quantum Fields and Strings

Mathematical physics
Large-N Collective Fields and de Sitter / CFT correspondence

Sumit Das University of Kentucky
September 25, 2012

PIRSA:12090045
Quantum Gravity

Quantum Fields and Strings
The Exploration of Hot QCD Matter

Berndt Mueller Duke University
September 11, 2012

PIRSA:12090046
Particle Physics
DT-invariants and $K_2$

Maxim Kontsevich Institut des Hautes Etudes Scientifiques (IHES)
August 23, 2012

PIRSA:12080009
Mathematical physics
Resurgence from the path integral perspective

Maxim Kontsevich Institut des Hautes Etudes Scientifiques (IHES)
August 21, 2012

PIRSA:12080008
Mathematical physics

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.
AdS(3)/CFT(2) correspondence and integrability

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 09, 2012

PIRSA:12100062
Quantum Fields and Strings

Mathematical physics
Integrability has been successfully used to compute the non-perturbative spectrum, Wilson loops and scattering amplitudes in the AdS/CFT correspondence. Most of these results apply to N=4, D=4 SYM / strings on AdS(5)xS(5). Strings on AdS(3)xM, where M is either S(3)xT(4) or S(3)xS(3)xS(1), are also integrable and potentially solvable by the same methods (Bethe ansatz, Y-system, TBA etc). An interesting aspect of string theory on AdS(3) is a large number of parameters that preserve integrability. One parameters, in particular, interpolates between the integrable RR AdS(3) background and conformal NSNS background described by a non-compact WZW model. Another interesting aspect of string theory on AdS(3) is emergence of target-space Viraroso symmetry. I will review how integrability arises in the AdS(3)/CFT(2) correspondence, and will describe what is (not) know about the Bethe ansatz solution of the relevant sigma-models.
Large-N Collective Fields and de Sitter / CFT correspondence

Sumit Das University of Kentucky
September 25, 2012

PIRSA:12090045
Quantum Gravity

Quantum Fields and Strings
We derive the collective theory of singlet fields of large-N Sp(N) spin models and display its unconventional features. Using the known relationship between O(N) collective fields and higher spin fields of Vasiliev theory in AdS space, we argue that the unique features of the Sp(N) collective theory suggest an interpretation in terms of a higher spin theory in de Sitter space, as proposed by Anninos, Hartman and Strominger. This is reminiscent of the way the Liouville mode is naturally interpreted as time in supercritical worldsheet string theory.
The Exploration of Hot QCD Matter

Berndt Mueller Duke University
September 11, 2012

PIRSA:12090046
Particle Physics
When nuclear matter is heated beyond a temperature of 2 trillion
degrees, it converts into a strongly coupled plasma of quarks and
gluons, the sQGP. Experiments using highly energetic collisions
between heavy nuclei have revealed that this new state of matter is a
nearly ideal, highly opaque liquid. A description based upon string
theory and black holes in five dimensions has made the quark- gluon
plasma an iconic example of a strongly coupled quantum system. In this
lecture I will survey the observed properties of the sQGP in the light
of the latest results from RHIC and LHC. On the theoretical side, I
will discuss the thermalization and entropy production problem and
origin and role of event-by-event fluctuations.
DT-invariants and $K_2$

Maxim Kontsevich Institut des Hautes Etudes Scientifiques (IHES)
August 23, 2012

PIRSA:12080009
Mathematical physics
TBA
Resurgence from the path integral perspective

Maxim Kontsevich Institut des Hautes Etudes Scientifiques (IHES)
August 21, 2012

PIRSA:12080008
Mathematical physics
TBA

Title	Speaker(s)	Date	Talk Type	Info
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
AdS(3)/CFT(2) correspondence and integrability	Konstantin Zarembo	2012-10-09	Scientific Series	View details
Large-N Collective Fields and de Sitter / CFT correspondence	Sumit Das	2012-09-25	Scientific Series	View details
The Exploration of Hot QCD Matter	Berndt Mueller	2012-09-11	Scientific Series	View details
DT-invariants and $K_2$	Maxim Kontsevich	2012-08-23	Scientific Series	View details
Resurgence from the path integral perspective	Maxim Kontsevich	2012-08-21	Scientific Series	View details

Quantum Fields and Strings

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