Talks

9793 - 9804 of 18100 Results

13/14 PSI - Foundations of Quantum Mechanics - Lecture 15

Lucien Hardy Perimeter Institute for Theoretical Physics

January 24, 2014

PIRSA:14010064
13/14 PSI - Gravitational Physics Review - Lecture 15

Ruth Gregory King's College London

January 24, 2014

PIRSA:14010045
13/14 PSI - Standard Model Review - Lecture 15

Paul Langacker Institute for Advanced Study (IAS)

January 24, 2014

PIRSA:14010026
Introduction to Effective Field Theories - Lecture 5

Cliff Burgess McMaster University

January 24, 2014

PIRSA:14010089
Introduction to Quantum Field Theory for Cosmology - Lecture 6

Achim Kempf University of Waterloo

January 23, 2014

PIRSA:14010006
Wilson Lines in Higher Spin Gravity

Alejandra Castro University of Cambridge

January 23, 2014

PIRSA:14010081

General Relativity & Quantum Cosmology
13/14 PSI - Foundations of Quantum Mechanics - Lecture 14

Lucien Hardy Perimeter Institute for Theoretical Physics

January 23, 2014

PIRSA:14010063
Cosmic Variance from Superhorizon Mode Coupling

Elliot Nelson IBM (United States)

January 23, 2014

PIRSA:14010107

Astrophysics
13/14 PSI - Gravitational Physics Review - Lecture 14

Ruth Gregory King's College London

January 23, 2014

PIRSA:14010044
13/14 PSI - Standard Model Review - Lecture 14

Paul Langacker Institute for Advanced Study (IAS)

January 23, 2014

PIRSA:14010025
Hardness of correcting errors on a stabilizer code

Pavithran Iyer

January 22, 2014

PIRSA:14010099

Quantum Physics
13/14 PSI - Foundations of Quantum Mechanics - Lecture 13

Lucien Hardy Perimeter Institute for Theoretical Physics

January 22, 2014

PIRSA:14010062

13/14 PSI - Foundations of Quantum Mechanics - Lecture 15

Lucien Hardy Perimeter Institute for Theoretical Physics

January 24, 2014

PIRSA:14010064
13/14 PSI - Gravitational Physics Review - Lecture 15

Ruth Gregory King's College London

January 24, 2014

PIRSA:14010045
13/14 PSI - Standard Model Review - Lecture 15

Paul Langacker Institute for Advanced Study (IAS)

January 24, 2014

PIRSA:14010026
Introduction to Effective Field Theories - Lecture 5

Cliff Burgess McMaster University

January 24, 2014

PIRSA:14010089
Introduction to Quantum Field Theory for Cosmology - Lecture 6

Achim Kempf University of Waterloo

January 23, 2014

PIRSA:14010006
Wilson Lines in Higher Spin Gravity

Alejandra Castro University of Cambridge

January 23, 2014

PIRSA:14010081

General Relativity & Quantum Cosmology

In this talk I will review the interpretation of Wilson line operators in the context of higher spin gravity in 2+1 dim and holography. I will show how a Wilson line encapsulates the thermodynamics of black holes. Furthermore it provides an elegant description of massive particles. This opens a new window of observables which will allow us to probe the true geometrical nature of higher spin gravity.
13/14 PSI - Foundations of Quantum Mechanics - Lecture 14

Lucien Hardy Perimeter Institute for Theoretical Physics

January 23, 2014

PIRSA:14010063
Cosmic Variance from Superhorizon Mode Coupling

Elliot Nelson IBM (United States)

January 23, 2014

PIRSA:14010107

Astrophysics

We observe a finite subvolume of the universe, so CMB and large scale structure data may give us either a representative or a biased sample of statistics in the larger universe. Mode coupling (non-Gaussianity) in the primordial perturbations can introduce a bias of parameters measured in any subvolume due to coupling to superhorizon background modes longer than the size of the subvolume. This leads to a "cosmic variance" of statistics on smaller scales, as the long-wavelength background modes vary around the global mean. We study this bias for local non-Gaussianity and quantify how observed statistics such as the power spectrum of the primordial perturbations, spectral index (scale-dependence in the power spectrum), amplitude of non-Gaussianity, dark matter halo power spectrum, and primordial tensor modes, can differ from the same quantities averaged throughout a volume much larger than the observable universe. More general kinds of mode coupling can change the relative sensitivity to different background modes. Finally, we consider what observations can tell us about the possibility of biasing from superhorizon modes."
13/14 PSI - Gravitational Physics Review - Lecture 14

Ruth Gregory King's College London

January 23, 2014

PIRSA:14010044
13/14 PSI - Standard Model Review - Lecture 14

Paul Langacker Institute for Advanced Study (IAS)

January 23, 2014

PIRSA:14010025
Hardness of correcting errors on a stabilizer code

Pavithran Iyer

January 22, 2014

PIRSA:14010099

Quantum Physics

Problems in computer science are often classified based on the scaling of the runtimes for algorithms that can solve the problem. Easy problems are efficiently solvable but often in physics we encounter problems that take too long to be solved on a classical computer. Here we look at one such problem in the context of quantum error correction. We will further show that no efficient algorithm for this problem is likely to exist. We will address the computational hardness of a decoding problem, pertaining to quantum stabilizer codes considering independent X and Z errors on each qubit. Much like classical linear codes, errors are detected by measuring certain check operators which yield an error syndrome, and the decoding problem consists of determining the most likely recovery given the syndrome. The corresponding classical problem is known to be NP-Complete, and a similar decoding problem for quantum codes is known to be NP-Complete too. However, this decoding strategy is not optimal in the quantum setting as it does not take into account error degeneracy, which causes distinct errors to have the same effect on the code. Here, we show that optimal decoding of stabilizer codes is computationally much harder than optimal decoding of classical linear codes, it is #P-Complete.
13/14 PSI - Foundations of Quantum Mechanics - Lecture 13

Lucien Hardy Perimeter Institute for Theoretical Physics

January 22, 2014

PIRSA:14010062

Title	Date	Collection	Type	Info
13/14 PSI - Foundations of Quantum Mechanics - Lecture 15	2014‑01‑24	13/14 PSI - Foundations of Quantum Mechanics	Course	View details
13/14 PSI - Gravitational Physics Review - Lecture 15	2014‑01‑24	13/14 PSI - Gravitational Physics Review	Course	View details
13/14 PSI - Standard Model Review - Lecture 15	2014‑01‑24	13/14 PSI - Standard Model Review	Course	View details
Introduction to Effective Field Theories - Lecture 5	2014‑01‑24	Introduction to Effective Field Theories	Course	View details
Introduction to Quantum Field Theory for Cosmology - Lecture 6	2014‑01‑23	Quantum Field Theory for Cosmology - 2014	Course	View details
Wilson Lines in Higher Spin Gravity	2014‑01‑23	Quantum Gravity	Scientific Series	View details
13/14 PSI - Foundations of Quantum Mechanics - Lecture 14	2014‑01‑23	13/14 PSI - Foundations of Quantum Mechanics	Course	View details
Cosmic Variance from Superhorizon Mode Coupling	2014‑01‑23	Cosmology and Gravitation	Scientific Series	View details
13/14 PSI - Gravitational Physics Review - Lecture 14	2014‑01‑23	13/14 PSI - Gravitational Physics Review	Course	View details
13/14 PSI - Standard Model Review - Lecture 14	2014‑01‑23	13/14 PSI - Standard Model Review	Course	View details
Hardness of correcting errors on a stabilizer code	2014‑01‑22	Perimeter Institute Quantum Discussions	Scientific Series	View details
13/14 PSI - Foundations of Quantum Mechanics - Lecture 13	2014‑01‑22	13/14 PSI - Foundations of Quantum Mechanics	Course	View details

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Format results

13/14 PSI - Foundations of Quantum Mechanics - Lecture 15

13/14 PSI - Gravitational Physics Review - Lecture 15

13/14 PSI - Standard Model Review - Lecture 15

Introduction to Effective Field Theories - Lecture 5

Introduction to Quantum Field Theory for Cosmology - Lecture 6

Wilson Lines in Higher Spin Gravity

13/14 PSI - Foundations of Quantum Mechanics - Lecture 14

Cosmic Variance from Superhorizon Mode Coupling

13/14 PSI - Gravitational Physics Review - Lecture 14

13/14 PSI - Standard Model Review - Lecture 14

Hardness of correcting errors on a stabilizer code

13/14 PSI - Foundations of Quantum Mechanics - Lecture 13

13/14 PSI - Foundations of Quantum Mechanics - Lecture 15

13/14 PSI - Gravitational Physics Review - Lecture 15

13/14 PSI - Standard Model Review - Lecture 15

Introduction to Effective Field Theories - Lecture 5

Introduction to Quantum Field Theory for Cosmology - Lecture 6

Wilson Lines in Higher Spin Gravity

13/14 PSI - Foundations of Quantum Mechanics - Lecture 14

Cosmic Variance from Superhorizon Mode Coupling

13/14 PSI - Gravitational Physics Review - Lecture 14

13/14 PSI - Standard Model Review - Lecture 14

Hardness of correcting errors on a stabilizer code

13/14 PSI - Foundations of Quantum Mechanics - Lecture 13