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Causality, holography, and entanglement entropy
February 20, 2014

PIRSA:14020146
General Relativity & Quantum Cosmology

High Energy Physics

Condensed Matter

General Relativity & Quantum Cosmology
13/14 PSI - Quantum Information Review - Lecture 3

Andrew Childs University of Waterloo

February 20, 2014

PIRSA:14020074
The emergent of the chiral spin liquid in kagome Heisenberg model

Dong-Ning Sheng California State University, Northridge
February 20, 2014

PIRSA:14020149
Condensed Matter
13/14 PSI - Quantum Gravity Review - Lecture 3

Bianca Dittrich Perimeter Institute for Theoretical Physics

February 20, 2014

PIRSA:14020063
13/14 PSI - Beyond the Standard Model - Lecture 2

Robert Mann University of Waterloo

February 20, 2014

PIRSA:14020052
Non equilibrium thermodynamic of gravitational screens

Laurent Freidel Perimeter Institute for Theoretical Physics
February 19, 2014

PIRSA:14020144
General Relativity & Quantum Cosmology

Mathematical Physics
13/14 PSI - Quantum Information Review - Lecture 2

Andrew Childs University of Waterloo

February 19, 2014

PIRSA:14020073
13/14 PSI - Quantum Gravity Review - Lecture 2

Bianca Dittrich Perimeter Institute for Theoretical Physics

February 19, 2014

PIRSA:14020062
13/14 PSI - Beyond the Standard Model - Lecture 1

Robert Mann University of Waterloo

February 19, 2014

PIRSA:14020051
Psi-epistemic models are exponentially bad at explaining the distinguishability of quantum states

Matthew Leifer Chapman University
February 18, 2014

PIRSA:14020145
Quantum Physics
Cluster Polylogarithms for Scattering Amplitudes
February 18, 2014

PIRSA:14020147
High Energy Physics
13/14 PSI - Quantum Information Review - Lecture 1

Andrew Childs University of Waterloo

February 18, 2014

PIRSA:14020072

Causality, holography, and entanglement entropy
February 20, 2014

PIRSA:14020146
General Relativity & Quantum Cosmology

High Energy Physics

Condensed Matter

General Relativity & Quantum Cosmology
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.
13/14 PSI - Quantum Information Review - Lecture 3

Andrew Childs University of Waterloo

February 20, 2014

PIRSA:14020074
The emergent of the chiral spin liquid in kagome Heisenberg model

Dong-Ning Sheng California State University, Northridge
February 20, 2014

PIRSA:14020149
Condensed Matter
The quantum spin liquid is an emergent new state of matter, which has attracted a lot of recent attention. In particular, the time reversal symmetry broken spin liquid (Kalmeyer et. al. and Wen et. al.), characterized by the chiral ordering and fractionalized quasi-particle as a realization of the fractional quantum Hall state had been proposed for more than 20 years, but never identified as the true ground state in any more generic (e.g. Heisenberg spin exchange) models with time reversal symmetry. Here I will report two concrete examples where chiral spin liquid (CSL) emerge for a range of parameter space for kagome J1-J2-J3 (three nearest neighbors) model based on accurate density matrix renormalization group (DMRG) simulations. We identify long-range chiral ordering, ground state degeneracy, characteristic entanglement spectra, and the fractionalized topological Chern number to establish the topological state in such a system as the long-sought CSL. We further explicitly extract the modular matrix, which captures all the information of the fractional statistics of the quasi-particles in the system. I will also discuss the close relation of our model to some frustrated kagome antiferromagnets, and make a conjecture that J1 kagome model is near an unconventional critical point. I will conclude the talk with some discussions of the open directions.
13/14 PSI - Quantum Gravity Review - Lecture 3

Bianca Dittrich Perimeter Institute for Theoretical Physics

February 20, 2014

PIRSA:14020063
13/14 PSI - Beyond the Standard Model - Lecture 2

Robert Mann University of Waterloo

February 20, 2014

PIRSA:14020052
Non equilibrium thermodynamic of gravitational screens

Laurent Freidel Perimeter Institute for Theoretical Physics
February 19, 2014

PIRSA:14020144
General Relativity & Quantum Cosmology

Mathematical Physics
In this talk I will review the evidence for a mysterious and deep relationship between gravitational dynamics and thermodynamics. I will show how we can extend this connection to non equilibrium thermodynamics. Using the fact that the gravitational equations are fundamentally holographic, we express them in a way that shows a deep connection between gravity and the dynamics of viscous bubbles. We will explore some aspects of this surprising correspondence.
13/14 PSI - Quantum Information Review - Lecture 2

Andrew Childs University of Waterloo

February 19, 2014

PIRSA:14020073
13/14 PSI - Quantum Gravity Review - Lecture 2

Bianca Dittrich Perimeter Institute for Theoretical Physics

February 19, 2014

PIRSA:14020062
13/14 PSI - Beyond the Standard Model - Lecture 1

Robert Mann University of Waterloo

February 19, 2014

PIRSA:14020051
Psi-epistemic models are exponentially bad at explaining the distinguishability of quantum states

Matthew Leifer Chapman University
February 18, 2014

PIRSA:14020145
Quantum Physics
The status of the quantum state is perhaps the most controversial issue in the foundations of quantum theory. Is it an epistemic state (representing knowledge, information, or belief) or an ontic state (a direct reflection of reality)? In the ontological models framework, quantum states correspond to probability measures over more fundamental states of reality. The quantum state is then ontic if every pair of pure states corresponds to a pair of measures that do not overlap, and is otherwise epistemic. Recently, several authors have derived theorems that aim to show that the quantum state must be ontic in this framework. Each of these theorems involve auxiliary assumptions of varying degrees of plausibility. Without such assumptions, it has been shown that models exist in which the quantum state is epistemic. However, the definition of an epistemic quantum state used in these works is extremely permissive. Only two quantum states need correspond to overlapping measures and furthermore the amount of overlap may be arbitrarily small. In order to provide an explanation of quantum phenomena such as no-cloning and the indistinguishability of pure states, the amount of overlap should be comparable to the inner product of the quantum states. In this talk, I show, without making auxiliary assumptions, that the ratio of overlap to inner product must go to zero exponentially in Hilbert space dimension for some families of states. This is done by connecting the overlap to Kochen-Specker noncontextuality, from which we infer that any contextuality inequality gives a bound on the ratio of overlap to inner product.
Cluster Polylogarithms for Scattering Amplitudes
February 18, 2014

PIRSA:14020147
High Energy Physics
Motivated by the cluster structure of two-loop scattering amplitudes in N = 4 Yang-Mills theory we define cluster polylogarithm functions. We find that all such functions of weight 4 are made up of a single simple building block associated to the A2 cluster algebra. Adding the requirement of locality on generalized Stasheff polytopes, we find that these A2 building blocks arrange themselves to form a unique function associated to the A3 cluster algebra. ThisA3 function manifests all of the cluster algebraic structure of the two-loop n-particle MHV amplitudes for all n, and we use it to provide an explicit representation for the most complicated part of the n = 7 amplitude as an example.
13/14 PSI - Quantum Information Review - Lecture 1

Andrew Childs University of Waterloo

February 18, 2014

PIRSA:14020072

Title	Date	Collection	Type	Info
Causality, holography, and entanglement entropy	2014‑02‑20	Quantum Fields and Strings	Scientific Series	View details
13/14 PSI - Quantum Information Review - Lecture 3	2014‑02‑20	13/14 PSI - Quantum Information Review	Course	View details
The emergent of the chiral spin liquid in kagome Heisenberg model	2014‑02‑20	Quantum Matter	Scientific Series	View details
13/14 PSI - Quantum Gravity Review - Lecture 3	2014‑02‑20	13/14 PSI - Quantum Gravity Review	Course	View details
13/14 PSI - Beyond the Standard Model - Lecture 2	2014‑02‑20	13/14 PSI - Beyond the Standard Model	Course	View details
Non equilibrium thermodynamic of gravitational screens	2014‑02‑19	Colloquium	Scientific Series	View details
13/14 PSI - Quantum Information Review - Lecture 2	2014‑02‑19	13/14 PSI - Quantum Information Review	Course	View details
13/14 PSI - Quantum Gravity Review - Lecture 2	2014‑02‑19	13/14 PSI - Quantum Gravity Review	Course	View details
13/14 PSI - Beyond the Standard Model - Lecture 1	2014‑02‑19	13/14 PSI - Beyond the Standard Model	Course	View details
Psi-epistemic models are exponentially bad at explaining the distinguishability of quantum states	2014‑02‑18	Quantum Foundations	Scientific Series	View details
Cluster Polylogarithms for Scattering Amplitudes	2014‑02‑18	Quantum Fields and Strings	Scientific Series	View details
13/14 PSI - Quantum Information Review - Lecture 1	2014‑02‑18	13/14 PSI - Quantum Information Review	Course	View details

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Format results

Causality, holography, and entanglement entropy

13/14 PSI - Quantum Information Review - Lecture 3

The emergent of the chiral spin liquid in kagome Heisenberg model

13/14 PSI - Quantum Gravity Review - Lecture 3

13/14 PSI - Beyond the Standard Model - Lecture 2

Non equilibrium thermodynamic of gravitational screens

13/14 PSI - Quantum Information Review - Lecture 2

13/14 PSI - Quantum Gravity Review - Lecture 2

13/14 PSI - Beyond the Standard Model - Lecture 1

Psi-epistemic models are exponentially bad at explaining the distinguishability of quantum states

Cluster Polylogarithms for Scattering Amplitudes

13/14 PSI - Quantum Information Review - Lecture 1

Causality, holography, and entanglement entropy

13/14 PSI - Quantum Information Review - Lecture 3

The emergent of the chiral spin liquid in kagome Heisenberg model

13/14 PSI - Quantum Gravity Review - Lecture 3

13/14 PSI - Beyond the Standard Model - Lecture 2

Non equilibrium thermodynamic of gravitational screens

13/14 PSI - Quantum Information Review - Lecture 2

13/14 PSI - Quantum Gravity Review - Lecture 2

13/14 PSI - Beyond the Standard Model - Lecture 1

Psi-epistemic models are exponentially bad at explaining the distinguishability of quantum states

Cluster Polylogarithms for Scattering Amplitudes

13/14 PSI - Quantum Information Review - Lecture 1