Quantum Fields and Strings

Displaying 385 - 396 of 725

Anomalies of discrete symmetries and Symmetry Protected Topological Phases

Anton Kapustin
California Institute of Technology (Caltech) - Division of Physics Mathematics & Astronomy
May 06, 2014

PIRSA:14050035
Quantum Fields and Strings
Probing renormalization group flows using entanglement entropy

Mark Mezei
Massachusetts Institute of Technology (MIT)
April 30, 2014

PIRSA:14040144
Quantum Fields and Strings
Localizing Braneworlds in Infinite Spaces

Kellogg Stelle
Imperial College London
April 29, 2014

PIRSA:14040064
Quantum Fields and Strings
3d N = 4 Gauge Theories, Mirror Symmetry and Hilbert series

Noppadol Mekareeya
Imperial College London
April 28, 2014

PIRSA:14040143
Quantum Fields and Strings
Causality constraints in gravitational theories
April 22, 2014

PIRSA:14040116
Quantum Fields and Strings
New Exact Results in Calabi-Yau, D-branes, and Orientifolds

Sungjay Lee
University of Cambridge
April 15, 2014

PIRSA:14040081
Quantum Fields and Strings
RG flows with N=1 supersymmetry

Henriette Elvang
University of Michigan–Ann Arbor
April 01, 2014

PIRSA:14030074
Quantum Fields and Strings
Far from equilibrium energy flow in quantum critical systems
March 25, 2014

PIRSA:14030089
Quantum Fields and Strings
Line Defects and Tropicalization

Clay Cordova
University of Chicago
March 11, 2014

PIRSA:14030106
Quantum Fields and Strings
How Much Information Can SUSY QM Conserve About SUSY QFT?

S. James Gates Jr.
University of Maryland, College Park
March 04, 2014

PIRSA:14030101
Quantum Fields and Strings
Quantum Liquids and Turbulent Black Holes

Allan Adams
Massachusetts Institute of Technology (MIT) - Department of Physics
February 24, 2014

PIRSA:14020141
Quantum Fields and Strings
Causality, holography, and entanglement entropy
February 20, 2014

PIRSA:14020146
Quantum Gravity

Quantum Fields and Strings

Condensed Matter

Strong Gravity

Anomalies of discrete symmetries and Symmetry Protected Topological Phases

Anton Kapustin
California Institute of Technology (Caltech) - Division of Physics Mathematics & Astronomy
May 06, 2014

PIRSA:14050035
Quantum Fields and Strings
There is a close connection between Symmetry Protected Topological Phases and anomalies: a surface of an SPT phase typically has a global symmetry with a nonvanishing 't Hooft anomaly which is canceled by the anomaly inflow from the bulk. This observation together with the known results about the classification of SPT phases suggest that anomalies are much more ubiquitous than thought previously and do not require chiral fermions We elucidate the physical mechanism of anomalies and give examples of bosonic theories with 't Hooft anomalies in various dimensions.
Probing renormalization group flows using entanglement entropy

Mark Mezei
Massachusetts Institute of Technology (MIT)
April 30, 2014

PIRSA:14040144
Quantum Fields and Strings
The entanglement entropy of the vacuum of a quantum field theory contains information about physics at all scales and is UV sensitive. A simple refinement of entanglement entropy gets rid of its UV divergence, and allows us to extract entanglement per scale. In two and three spacetime dimensions this quantity can be used as a proxy for the number of degrees of freedom, as it decreases under RG flow. We investigate its behavior around fixed points, and reveal its interesting analytic structure in the space of couplings.
Localizing Braneworlds in Infinite Spaces

Kellogg Stelle
Imperial College London
April 29, 2014

PIRSA:14040064
Quantum Fields and Strings
There have been a number of attempts to achieve a localization of gravity on a braneworld hypersurface embedded in an infinite spacetime, but these have all fallen short of what might be desired, for various reasons. There have even been no-go theorems claimed for constructions made using just accepted elements of string or M theory. The talk will present a proposed resolution of this problem based upon a hyperbolic solution of type IIA theory with a superposed NS-5 brane. Gravity is bound to the brane surface owing to the existence of a single normalizable bound state of the transverse space Laplacian.
3d N = 4 Gauge Theories, Mirror Symmetry and Hilbert series

Noppadol Mekareeya
Imperial College London
April 28, 2014

PIRSA:14040143
Quantum Fields and Strings
This talk focuses on vacuum moduli spaces of N=4 supersymmetric field theories in three dimensions. A particular branch of the moduli space, known as the Coulomb branch, receives quantum corrections. We present an exact result, known as the Hilbert series, that enumerates the operators in the chiral ring of such a quantum Coulomb branch. This exact result can be applied to a large class of 3d supersymmetric field theories, with and without known Lagrangian descriptions. As an application, we present a method to compute partition functions of instantons on C^2 for any simple group, including exceptional and non-simply-laced ones.
Causality constraints in gravitational theories
April 22, 2014

PIRSA:14040116
Quantum Fields and Strings
New Exact Results in Calabi-Yau, D-branes, and Orientifolds

Sungjay Lee
University of Cambridge
April 15, 2014

PIRSA:14040081
Quantum Fields and Strings
We compute the exact two-sphere, disk and real projective plane partition functions of two-dimensional supersymmetric theories using the localization technique. From these new results, we will attack old and new important problems in the string theory on Calabi-Yau spaces, and D-branes and Orientifold planes therein.
RG flows with N=1 supersymmetry

Henriette Elvang
University of Michigan–Ann Arbor
April 01, 2014

PIRSA:14030074
Quantum Fields and Strings
The dilaton effective action plays a key role for the recent proof of the a-theorem by Schwimmer and Komargodski. In the presence of other massless modes, one may ask if this proof is affected. In particular, in renormalization group (RG) flows with N=1 supersymmetry, there is a natural massless partner of the dilaton, namely an axion field. I will discuss RG flows, the a-theorem, and the form of the N=1 supersymmetric dilaton-axion effective action and its physics.
Far from equilibrium energy flow in quantum critical systems
March 25, 2014

PIRSA:14030089
Quantum Fields and Strings
We investigate far from equilibrium energy transport in strongly coupled quantum critical systems. Combining results from gauge-gravity duality, relativistic hydrodynamics, and quantum field theory, we argue that long-time energy transport after a local thermal quench occurs via a universal steady-state for any spatial dimensionality. This is described by a boosted thermal state. We determine the transport properties of this emergent steady state, including the average energy flow and its long-time fluctuations.
Line Defects and Tropicalization

Clay Cordova
University of Chicago
March 11, 2014

PIRSA:14030106
Quantum Fields and Strings
I will review BPS line defects in 4d N=2 field theories and describe a technique for calculating their spectra using quiver quantum mechanics.
How Much Information Can SUSY QM Conserve About SUSY QFT?

S. James Gates Jr.
University of Maryland, College Park
March 04, 2014

PIRSA:14030101
Quantum Fields and Strings
In this presentation, evidence is given that supersymmetrical theories may be exceptional in their ability to conserve information about space-time representations under the impact of dimensional compactification. This is the essence of the concept of ``SUSY Holography.''
Quantum Liquids and Turbulent Black Holes

Allan Adams
Massachusetts Institute of Technology (MIT) - Department of Physics
February 24, 2014

PIRSA:14020141
Quantum Fields and Strings
The physics of black hole horizons is intimately connected to the physics of quantum liquids. In this talk I will review the connection and draw lessons about quantum turbulence from black hole dynamics and vice versa. For example, gravitational dynamics reveal that quantum turbulence can behave very differently from normal fluid turbulence in 2d, with long-wavelength excitations rapidly dissolving into small fluctuations and dissipating as in a 3d normal liquid. Meanwhile, familiar facts about turbulent flows in normal fluids imply that the horizons of certain accreting black holes evolve in time as if they have a non-trivial fractal dimension.
Causality, holography, and entanglement entropy
February 20, 2014

PIRSA:14020146
Quantum Gravity

Quantum Fields and Strings

Condensed Matter

Strong Gravity
After giving a brief overview of holographic entanglement entropy formulas, I will explore a curious feature they imply: when the bulk spacetime includes a black hole, the entanglement entropies often appear to depend on the spacetime geometry inside the horizon. I will ask whether this implies any loss of causality in the field theory. To answer this question, I will present a new general-relativity theorem concerning the causal structure of asymptotically AdS spacetimes, which implies an interesting relationship between bulk and boundary causal domains.

Title	Speaker(s)	Date	Talk Type	Info
Anomalies of discrete symmetries and Symmetry Protected Topological Phases	Anton Kapustin	2014-05-06	Scientific Series	View details
Probing renormalization group flows using entanglement entropy	Mark Mezei	2014-04-30	Scientific Series	View details
Localizing Braneworlds in Infinite Spaces	Kellogg Stelle	2014-04-29	Scientific Series	View details
3d N = 4 Gauge Theories, Mirror Symmetry and Hilbert series	Noppadol Mekareeya	2014-04-28	Scientific Series	View details
Causality constraints in gravitational theories		2014-04-22	Scientific Series	View details
New Exact Results in Calabi-Yau, D-branes, and Orientifolds	Sungjay Lee	2014-04-15	Scientific Series	View details
RG flows with N=1 supersymmetry	Henriette Elvang	2014-04-01	Scientific Series	View details
Far from equilibrium energy flow in quantum critical systems		2014-03-25	Scientific Series	View details
Line Defects and Tropicalization	Clay Cordova	2014-03-11	Scientific Series	View details
How Much Information Can SUSY QM Conserve About SUSY QFT?	S. James Gates Jr.	2014-03-04	Scientific Series	View details
Quantum Liquids and Turbulent Black Holes	Allan Adams	2014-02-24	Scientific Series	View details
Causality, holography, and entanglement entropy		2014-02-20	Scientific Series	View details

Quantum Fields and Strings

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