Talks

10849 - 10860 of 18093 Results

Modified Gravity, Dark Matter and Dark Energy: Deep Mysteries of the Universe

John Moffat Perimeter Institute for Theoretical Physics

November 14, 2012

PIRSA:12110074

Astrophysics
Massive gravitons, the cosmological constant and new directions in gravity

November 14, 2012

PIRSA:12110061

Astrophysics
Statistical Mechanics - Lecture 3

John Berlinsky McMaster University

November 14, 2012

PIRSA:12110021
Quantum Field Theory 2 - Lecture 3

Francois David CEA Saclay

November 14, 2012

PIRSA:12110002

High Energy Physics
Quasiprobability representations of qubits

November 13, 2012

PIRSA:12110070
Anomaly-induced transport and thermodynamics

Kristan Jensen University of Victoria

November 13, 2012

PIRSA:12110047

High Energy Physics
Stealthy, Composite Stops

Philip Tanedo Cornell University

November 13, 2012

PIRSA:12110063

High Energy Physics
Recent progress on de Sitter S-matrix

Ian Morrison West Chester University

November 13, 2012

PIRSA:12110043

Astrophysics
Statistical Mechanics - Lecture 2

John Berlinsky McMaster University

November 13, 2012

PIRSA:12110020
Quantum Field Theory 2 - Lecture 2

Francois David CEA Saclay

November 13, 2012

PIRSA:12110001

High Energy Physics
Statistical Mechanics - Lecture 1

John Berlinsky McMaster University

November 12, 2012

PIRSA:12110019
Quantum Field Theory 2 - Lecture 1

Francois David CEA Saclay

November 12, 2012

PIRSA:12110000

High Energy Physics

Modified Gravity, Dark Matter and Dark Energy: Deep Mysteries of the Universe

John Moffat Perimeter Institute for Theoretical Physics

November 14, 2012

PIRSA:12110074

Astrophysics
Massive gravitons, the cosmological constant and new directions in gravity

November 14, 2012

PIRSA:12110061

Astrophysics

The solutions to the cosmological constant problems may involve modifying the very long-range dynamics of gravity by adding new degrees of freedom. As an example of a conservative and minimal such modification, we consider the possibility that the graviton has a very small mass. Massive gravity has received renewed interest due to recent advances which have resolved its traditional problems. This kind of modification has some peculiar and unexpected features, and it points us towards a universe which looks quite unfamiliar.
Support for this colloquium is provided by The Templeton Frontiers Program.
Statistical Mechanics - Lecture 3

John Berlinsky McMaster University

November 14, 2012

PIRSA:12110021
Quantum Field Theory 2 - Lecture 3

Francois David CEA Saclay

November 14, 2012

PIRSA:12110002

High Energy Physics
Quasiprobability representations of qubits

November 13, 2012

PIRSA:12110070

Negativity in a quasi-probability representation is typically interpreted as an indication of nonclassical behavior. However, this does not preclude bases that are non-negative from having interesting applications---the single-qubit stabilizer states have non-negative Wigner functions and yet play a fundamental role in many quantum information tasks. We determine what other sets of quantum states and measurements of a qubit can be non-negative in a quasiprobability representation, and identify nontrivial groups of unitary transformations that permute such states. These sets of states and measurements are analogous to the single-qubit stabilizer states. We show that no quasiprobability representation of a qubit can be non-negative for more than two bases in any plane of the Bloch sphere. Furthermore, there is a single family of sets of four bases that can be non-negative in an arbitrary quasiprobability representation of a qubit. We provide an exhaustive list of the sets of single-qubit bases that are nonnegative in some quasiprobability representation and are also closed under a group of unitary transformations, revealing two families of such sets of three bases. We also show that not all two-qubit Clifford transformations can preserve non-negativity in any quasiprobability representation that is non-negative for the computational basis. This is in stark contrast to the qutrit case, in which the discrete Wigner function is non-negative for all n-qutrit stabilizer states and Clifford transformations. We also provide some evidence that extending the other sets of non-negative single-qubit states to multiple qubits does not give entangled states.
Anomaly-induced transport and thermodynamics

Kristan Jensen University of Victoria

November 13, 2012

PIRSA:12110047

High Energy Physics

I will discuss recent progress in the study of anomaly-induced transport, focusing on the chiral vortical effect in 3+1 dimensions. Most of my discussion will be framed in light of a larger story, namely progress in making exact statements about finite-temperature quantum field theory, for which the chiral magnetic and vortical effects are instructive prototypes.
Stealthy, Composite Stops

Philip Tanedo Cornell University

November 13, 2012

PIRSA:12110063

High Energy Physics

Light third generation superpartners are one way to avoid bounds on new physics from the early LHC. We will review the theory and phenomenology of light stops and highlight a particular UV model based a partially composite electroweak sector through Seiberg duality.
Recent progress on de Sitter S-matrix

Ian Morrison West Chester University

November 13, 2012

PIRSA:12110043

Astrophysics

The de Sitter S-matrix provides a gauge-invariant and field redefinition-invariant window into de Sitter QFTs and may provide a crucial entry in any dS/CFT dictionary. In this talk I will summarize recent progress on developing the S-matrix for theories with gauge fields and perturbative gravity. Nonrenormalization theorems, hints of supersymmetry, and perturbative stability will be discussed.
Statistical Mechanics - Lecture 2

John Berlinsky McMaster University

November 13, 2012

PIRSA:12110020
Quantum Field Theory 2 - Lecture 2

Francois David CEA Saclay

November 13, 2012

PIRSA:12110001

High Energy Physics
Statistical Mechanics - Lecture 1

John Berlinsky McMaster University

November 12, 2012

PIRSA:12110019
Quantum Field Theory 2 - Lecture 1

Francois David CEA Saclay

November 12, 2012

PIRSA:12110000

High Energy Physics

Title	Date	Collection	Type	Info
Modified Gravity, Dark Matter and Dark Energy: Deep Mysteries of the Universe	2012‑11‑14	Cosmology and Gravitation	Other	View details
Massive gravitons, the cosmological constant and new directions in gravity	2012‑11‑14	Colloquium	Scientific Series	View details
Statistical Mechanics - Lecture 3	2012‑11‑14	12/13 PSI - Statistical Mechanics	Course	View details
Quantum Field Theory 2 - Lecture 3	2012‑11‑14	12/13 PSI - Quantum Field Theory 2	Course	View details
Quasiprobability representations of qubits	2012‑11‑13	Quantum Foundations	Scientific Series	View details
Anomaly-induced transport and thermodynamics	2012‑11‑13	Quantum Fields and Strings	Scientific Series	View details
Stealthy, Composite Stops	2012‑11‑13	Particle Physics	Scientific Series	View details
Recent progress on de Sitter S-matrix	2012‑11‑13	Cosmology and Gravitation	Scientific Series	View details
Statistical Mechanics - Lecture 2	2012‑11‑13	12/13 PSI - Statistical Mechanics	Course	View details
Quantum Field Theory 2 - Lecture 2	2012‑11‑13	12/13 PSI - Quantum Field Theory 2	Course	View details
Statistical Mechanics - Lecture 1	2012‑11‑12	12/13 PSI - Statistical Mechanics	Course	View details
Quantum Field Theory 2 - Lecture 1	2012‑11‑12	12/13 PSI - Quantum Field Theory 2	Course	View details

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Format results

Modified Gravity, Dark Matter and Dark Energy: Deep Mysteries of the Universe

Massive gravitons, the cosmological constant and new directions in gravity

Statistical Mechanics - Lecture 3

Quantum Field Theory 2 - Lecture 3

Quasiprobability representations of qubits

Anomaly-induced transport and thermodynamics

Stealthy, Composite Stops

Recent progress on de Sitter S-matrix

Statistical Mechanics - Lecture 2

Quantum Field Theory 2 - Lecture 2

Statistical Mechanics - Lecture 1

Quantum Field Theory 2 - Lecture 1

Modified Gravity, Dark Matter and Dark Energy: Deep Mysteries of the Universe

Massive gravitons, the cosmological constant and new directions in gravity

Statistical Mechanics - Lecture 3

Quantum Field Theory 2 - Lecture 3

Quasiprobability representations of qubits

Anomaly-induced transport and thermodynamics

Stealthy, Composite Stops

Recent progress on de Sitter S-matrix

Statistical Mechanics - Lecture 2

Quantum Field Theory 2 - Lecture 2

Statistical Mechanics - Lecture 1

Quantum Field Theory 2 - Lecture 1