Quantum Fields and Strings

Displaying 433 - 444 of 732

Quantum Computation vs. Firewalls

Daniel Harlow Massachusetts Institute of Technology (MIT)
February 26, 2013

PIRSA:13020138
Quantum Information

Quantum Fields and Strings
Wall-Crossing and Quiver Invariants

Piljin Yi Korea Institute for Advanced Study
February 19, 2013

PIRSA:13020137
Quantum Fields and Strings
Time Crystals

Alfred Shapere University of Kentucky
February 05, 2013

PIRSA:13020121
Quantum Fields and Strings
How to Fall into a Black Hole

Herman Verlinde Princeton University
January 29, 2013

PIRSA:13010020
Quantum Fields and Strings
A monodromy defect in the 3d Ising model.

Roberto Pellegrini National Institute for Nuclear Physics
January 22, 2013

PIRSA:13010106
Quantum Fields and Strings
Superhorizon fluctuations in de Sitter and cosmological spacetimes

Guilherme Pimentel Universiteit van Amsterdam
January 15, 2013

PIRSA:13010001
Quantum Fields and Strings

Cosmology
Worldsheet form factors in AdS/CFT

Tristan McLoughlin Trinity College Dublin
January 08, 2013

PIRSA:13010022
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
(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

Quantum Computation vs. Firewalls

Daniel Harlow Massachusetts Institute of Technology (MIT)
February 26, 2013

PIRSA:13020138
Quantum Information

Quantum Fields and Strings
Wall-Crossing and Quiver Invariants

Piljin Yi Korea Institute for Advanced Study
February 19, 2013

PIRSA:13020137
Quantum Fields and Strings
We start with a one-slide review of the Kontsevich-Soibelman (KS) solution to the wall-crossing problem and then proceed to direct and comprehensive physics counting of BPS states that eventually connects to KS. We also asks what input data is needed for either approaches to produce complete BPS spectra, and this naturally leads to the BPS quiver representation of BPS states and the new notion of quiver invariants.
We propose a simple geometrical conjecture that can segregate BPS states in Higgs phases of the BPS quiver dynamics to those that experience wall-crossing and those that do not, and give
proofs for all cyclice Abelian quivers. We close with explanation of how physics distinguishes two such classes of BPS states.
Time Crystals

Alfred Shapere University of Kentucky
February 05, 2013

PIRSA:13020121
Quantum Fields and Strings
I consider a class of simple classical systems which exhibit motion in their lowest-energy states and thus spontaneously break time-translation symmetry. Their Lagrangians have nonstandard kinetic terms and their Hamiltonians are multivalued functions of momentum, yet they are perfectly consistent and amenable to quantization. Field theoretical generalizations of these systems may have applications in condensed matter physics and cosmology.
How to Fall into a Black Hole

Herman Verlinde Princeton University
January 29, 2013

PIRSA:13010020
Quantum Fields and Strings
In this talk I investigate the "firewall argument", that claims that black hole horizons can not be smooth. Using a holographic model of the black hole horizon as a quantum mechanical membrane, I show how to recover the black hole interior as an emergent smooth region of space-time. The reconstruction makes use of the formalism of quantum error correcting codes. I explain why the horizon of very old black holes appears to be singular, and formulate a complementarity principle that resolves this firewall paradox.
A monodromy defect in the 3d Ising model.

Roberto Pellegrini National Institute for Nuclear Physics
January 22, 2013

PIRSA:13010106
Quantum Fields and Strings
A conformal defect is a d-dimensional geometrical object that breaks the SO(D+1,1) symmetry, of a D-dimensional conformal field theory, down to those transformations that leave the defect invariant i.e. SO(D-d) X SO(d+1,1).
We studied the 3D critical Ising model in presence of a special kind of these defects, a monodromy line defect.
In particular we computed, using Montecarlo simulations, the anomalous dimensions of the lowest dimensional operators living at the defect, as well as correlation functions of operators in the bulk with operators at the defect.
We found a good agreement between our results and the expectations of conformal field theory.
Superhorizon fluctuations in de Sitter and cosmological spacetimes

Guilherme Pimentel Universiteit van Amsterdam
January 15, 2013

PIRSA:13010001
Quantum Fields and Strings

Cosmology
I will discuss superhorizon fluctuations in de Sitter space. The first part of the talk will focus on computing entanglement entropies of field theories in a fixed de Sitter background. Those computations are done for free theories and also theories with gravity duals. If time permits, I will also discuss superhorizon fluctuations in cosmological backgrounds. In particular, I focus on showing that subhorizon fluctuations can not produce any significant backreaction on superhorizon modes. If those late time effects existed, one in principle could not trust the scale invariant spectrum of inflationary theories to be the source of the spectrum of thermal fluctuations of the CMB.
Worldsheet form factors in AdS/CFT

Tristan McLoughlin Trinity College Dublin
January 08, 2013

PIRSA:13010022
Quantum Fields and Strings
The study of the worldsheet S-matrix for AdS_5×S^5 strings was a key step in the complete determination of the non-pertubrative planar spectrum of anomalous dimensions for N=4 super-Yang-Mills. To go beyond the spectral problem it is important to consider higher-point worldsheet correlation functions and, as is standard in many integrable models, one approach is the study of form factors. We will discuss a set of consistency conditions appropriate to form factors in the light-cone gauge fixed AdS_5×S^5 string theory. We further discuss the form factors in the weakly coupled dual description, verifying that the relevant conditions naturally hold for the one-loop Heisenberg spin-chain.
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.

Title	Speaker(s)	Date	Talk Type	Info
Quantum Computation vs. Firewalls	Daniel Harlow	2013-02-26	Scientific Series	View details
Wall-Crossing and Quiver Invariants	Piljin Yi	2013-02-19	Scientific Series	View details
Time Crystals	Alfred Shapere	2013-02-05	Scientific Series	View details
How to Fall into a Black Hole	Herman Verlinde	2013-01-29	Scientific Series	View details
A monodromy defect in the 3d Ising model.	Roberto Pellegrini	2013-01-22	Scientific Series	View details
Superhorizon fluctuations in de Sitter and cosmological spacetimes	Guilherme Pimentel	2013-01-15	Scientific Series	View details
Worldsheet form factors in AdS/CFT	Tristan McLoughlin	2013-01-08	Scientific Series	View details
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

Quantum Fields and Strings

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