Talks

10261 - 10272 of 16661 Results

12/13 PSI - Explorations in Cosmology Lecture 8

Matthew Johnson York University

April 17, 2013

PIRSA:13040071

Cosmology
The theory of composition in physics

Lucien Hardy Perimeter Institute for Theoretical Physics

April 16, 2013

PIRSA:13040121

Quantum Foundations
12/13 PSI - Explorations in String Theory Lecture 7

Pedro Vieira Perimeter Institute for Theoretical Physics

April 16, 2013

PIRSA:13040092

Quantum Fields and Strings
Results and highlights from Planck

Kendrick Smith Perimeter Institute for Theoretical Physics

April 16, 2013

PIRSA:13040123

Cosmology
12/13 PSI - Explorations in Cosmology Lecture 7

Matthew Johnson York University

April 16, 2013

PIRSA:13040070

Cosmology
Continuous-variable entanglement distillation and non-commutative central limit theorems

Earl Campbell University of Sheffield

April 15, 2013

PIRSA:13040122

Quantum Information
12/13 PSI - Explorations in String Theory Lecture 6

Pedro Vieira Perimeter Institute for Theoretical Physics

April 15, 2013

PIRSA:13040091

Quantum Fields and Strings
12/13 PSI - Explorations in Cosmology Lecture 6

Matthew Johnson York University

April 15, 2013

PIRSA:13040069

Cosmology
12/13 PSI - Explorations in String Theory Lecture 5

Pedro Vieira Perimeter Institute for Theoretical Physics

April 12, 2013

PIRSA:13040088

Quantum Fields and Strings
12/13 PSI - Explorations in Cosmology Lecture 5

Matthew Johnson York University

April 12, 2013

PIRSA:13040066

Cosmology
Advanced General Relativity - Lecture 24

Rafael Sorkin Perimeter Institute for Theoretical Physics

April 11, 2013

PIRSA:13040010
Quantum causal dynamics without absolute space or time

April 11, 2013

PIRSA:13040083

Quantum Gravity

12/13 PSI - Explorations in Cosmology Lecture 8

Matthew Johnson York University

April 17, 2013

PIRSA:13040071

Cosmology
The theory of composition in physics

Lucien Hardy Perimeter Institute for Theoretical Physics

April 16, 2013

PIRSA:13040121

Quantum Foundations

We develop a theory for describing composite objects in physics. These can be static objects, such as tables, or things that happen in spacetime (such as a region of spacetime with fields on it regarded as being composed of smaller such regions joined together). We propose certain fundamental axioms which, it seems, should be satisfied in any theory of composition. A key axiom is the order independence axiom which says we can describe the composition of a composite object in any order. Then we provide a notation for describing composite objects that naturally leads to these axioms being satisfied. In any given physical context we are interested in the value of certain properties for the objects (such as whether the object is possible, what probability it has, how wide it is, and so on). We associate a generalized state with an object. This can be used to calculate the value of those properties we are interested in for for this object. We then propose a certain principle, the composition principle, which says that we can determine the generalized state of a composite object from the generalized states for the components by means of a calculation having the same structure as the description of the generalized state. The composition principle provides a link between description and prediction.
12/13 PSI - Explorations in String Theory Lecture 7

Pedro Vieira Perimeter Institute for Theoretical Physics

April 16, 2013

PIRSA:13040092

Quantum Fields and Strings
Results and highlights from Planck

Kendrick Smith Perimeter Institute for Theoretical Physics

April 16, 2013

PIRSA:13040123

Cosmology

Cosmological results from Planck, a third-generation satellite mission to measure the cosmic microwave background, have just been announced. These results improve constraints on essentially all cosmological parameters, and have implications for several preexisting sources of tension with the standard cosmological model, while also raising new puzzles. I will discuss these results and their significance, as well as the next steps forward.
12/13 PSI - Explorations in Cosmology Lecture 7

Matthew Johnson York University

April 16, 2013

PIRSA:13040070

Cosmology
Continuous-variable entanglement distillation and non-commutative central limit theorems

Earl Campbell University of Sheffield

April 15, 2013

PIRSA:13040122

Quantum Information

Entanglement distillation transforms weakly entangled noisy states into highly entangled states, a primitive to be used in quantum repeater schemes and other protocols designed for quantum communication and key distribution. In this work, we present a comprehensive framework for continuous-variable entanglement distillation schemes that convert noisy non-Gaussian states into Gaussian ones in many iterations of the protocol. Instances of these protocols include the recursive Gaussifier protocol and the pumping Gaussifier protocol. The flexibility of these protocols give rise to several beneficial trade-offs related to success probabilities or memory requirements that can be adjusted to reflect experimental specifics. Despite these protocols involving measurements, we relate the convergence in this protocols to new instances of non-commutative central limit theorems. Implications of the findings for quantum repeater schemes are discussed.
12/13 PSI - Explorations in String Theory Lecture 6

Pedro Vieira Perimeter Institute for Theoretical Physics

April 15, 2013

PIRSA:13040091

Quantum Fields and Strings
12/13 PSI - Explorations in Cosmology Lecture 6

Matthew Johnson York University

April 15, 2013

PIRSA:13040069

Cosmology
12/13 PSI - Explorations in String Theory Lecture 5

Pedro Vieira Perimeter Institute for Theoretical Physics

April 12, 2013

PIRSA:13040088

Quantum Fields and Strings
12/13 PSI - Explorations in Cosmology Lecture 5

Matthew Johnson York University

April 12, 2013

PIRSA:13040066

Cosmology
Advanced General Relativity - Lecture 24

Rafael Sorkin Perimeter Institute for Theoretical Physics

April 11, 2013

PIRSA:13040010
Quantum causal dynamics without absolute space or time

April 11, 2013

PIRSA:13040083

Quantum Gravity

I will describe a discrete model of spacetime which is quantum-mechanical, causal, and background free. The kinematics is described by networks whose vertices are labelled with arrows. These networks can be evolved forwards (or backwards) in time by using unitary replacement rules. The arrow structure permits one to define dynamics without using an absolute time parameter. Based on arXiv:1201.2489.

Title	Date	Collection	Type	Info
12/13 PSI - Explorations in Cosmology Lecture 8	2013‑04‑17	12/13 PSI - Explorations in Cosmology	Course	View details
The theory of composition in physics	2013‑04‑16	Quantum Foundations	Scientific Series	View details
12/13 PSI - Explorations in String Theory Lecture 7	2013‑04‑16	12/13 PSI - Eplorations in String Theory	Course	View details
Results and highlights from Planck	2013‑04‑16	Cosmology and Gravitation	Scientific Series	View details
12/13 PSI - Explorations in Cosmology Lecture 7	2013‑04‑16	12/13 PSI - Explorations in Cosmology	Course	View details
Continuous-variable entanglement distillation and non-commutative central limit theorems	2013‑04‑15	Perimeter Institute Quantum Discussions	Scientific Series	View details
12/13 PSI - Explorations in String Theory Lecture 6	2013‑04‑15	12/13 PSI - Eplorations in String Theory	Course	View details
12/13 PSI - Explorations in Cosmology Lecture 6	2013‑04‑15	12/13 PSI - Explorations in Cosmology	Course	View details
12/13 PSI - Explorations in String Theory Lecture 5	2013‑04‑12	12/13 PSI - Eplorations in String Theory	Course	View details
12/13 PSI - Explorations in Cosmology Lecture 5	2013‑04‑12	12/13 PSI - Explorations in Cosmology	Course	View details
Advanced General Relativity - Lecture 24	2013‑04‑11	Elements of General Relativity	Course	View details
Quantum causal dynamics without absolute space or time	2013‑04‑11	Quantum Gravity	Scientific Series	View details

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