Talks

10861 - 10872 of 19186 Results

13/14 PSI - Explorations in Condensed Matter - Lecture 9

Guifre Vidal Alphabet (United States)

March 27, 2014

PIRSA:14040032
13/14 PSI - Explorations in Quantum Information - Lecture 9

David Cory Institute for Quantum Computing (IQC)

March 27, 2014

PIRSA:14030039
The invasion of physics by information theory

Robert Spekkens Perimeter Institute for Theoretical Physics

March 26, 2014

PIRSA:14030085

Quantum Physics
13/14 PSI - Explorations in String Theory - Lecture 8

Andrei Starinets University of Oxford

March 26, 2014

PIRSA:14030068
GeV Gamma-Rays from the Central Milky Way and the Case for Annihilating Dark Matter

Tracy Slatyer Massachusetts Institute of Technology (MIT) - Department of Physics

March 26, 2014

PIRSA:14030120

High Energy Physics
13/14 PSI - Explorations in Condensed Matter - Lecture 8

Guifre Vidal Alphabet (United States)

March 26, 2014

PIRSA:14040031
13/14 PSI - Explorations in Quantum Information - Lecture 8

David Cory Institute for Quantum Computing (IQC)

March 26, 2014

PIRSA:14030038
Introduction to Quantum Field Theory for Cosmology - Lecture 21

Achim Kempf University of Waterloo

March 25, 2014

PIRSA:14030002
Far from equilibrium energy flow in quantum critical systems

March 25, 2014

PIRSA:14030089

High Energy Physics
Naturalness and the Weak Gravity Conjecture

Clifford Cheung California Institute of Technology (Caltech) - Physics Office

March 25, 2014

PIRSA:14030119

High Energy Physics
13/14 PSI - Explorations in String Theory - Lecture 7

Andrei Starinets University of Oxford

March 25, 2014

PIRSA:14030067
Cosmic initial conditions and the CMB

Daniel Grin California Institute of Technology

March 25, 2014

PIRSA:14030112

Astrophysics

13/14 PSI - Explorations in Condensed Matter - Lecture 9

Guifre Vidal Alphabet (United States)

March 27, 2014

PIRSA:14040032
13/14 PSI - Explorations in Quantum Information - Lecture 9

David Cory Institute for Quantum Computing (IQC)

March 27, 2014

PIRSA:14030039
The invasion of physics by information theory

Robert Spekkens Perimeter Institute for Theoretical Physics

March 26, 2014

PIRSA:14030085

Quantum Physics

When we think of a revolution in physics, we usually think of a physical theory that manages to overthrow its predecessor. There is another kind of revolution, however, that typically happens more slowly but that is often the key to achieving the first sort: it is the discovery of a novel perspective on an existing physical theory. The use of least-action principles, symmetry principles, and thermodynamic principles are good historical examples. It turns out that we can refine our understanding of many of these principles by characterizing certain properties of physical states as resources. I will discuss some of the highlights of two resource theories: the resource theory of asymmetry, which characterizes the relations among quantum states that break a symmetry; and the resource theory of athermality, which characterizes the relations among quantum states that deviate from thermal equilibrium. In particular, I will discuss how Noether's theorem does not capture all of the consequences of symmetries of the dynamics, and how the second law of thermodynamics does not capture all of the constraints on thermodynamic transitions. Finally, I will show that both asymmetry and athermality are informational resources, and that rehabilitated versions of Noether's theorem and the second law can both be understood as constraints on data processing. Considerations such as these---as well as evidence from other fronts of the invasion---make a compelling case for the revolutionary cause of reconceiving physics from an information-theoretic perspective.
13/14 PSI - Explorations in String Theory - Lecture 8

Andrei Starinets University of Oxford

March 26, 2014

PIRSA:14030068
GeV Gamma-Rays from the Central Milky Way and the Case for Annihilating Dark Matter

Tracy Slatyer Massachusetts Institute of Technology (MIT) - Department of Physics

March 26, 2014

PIRSA:14030120

High Energy Physics

Past studies have identified a spatially extended excess of ~1-3 GeV gamma rays from the Galactic Center and inner Galaxy, consistent with the emission expected from annihilating thermal relic dark matter. I will describe recent improvements in the characterization of this signal, which demonstrate that it is spherically symmetric, centered on the Galactic Center, and with a spatial profile consistent with annihilation from a cusped NFW profile. The excess can be detected out to 10 degrees from the Galactic Center, which poses challenges for a millisecond pulsar origin; I will discuss the implications of a dark matter interpretation.
13/14 PSI - Explorations in Condensed Matter - Lecture 8

Guifre Vidal Alphabet (United States)

March 26, 2014

PIRSA:14040031
13/14 PSI - Explorations in Quantum Information - Lecture 8

David Cory Institute for Quantum Computing (IQC)

March 26, 2014

PIRSA:14030038
Introduction to Quantum Field Theory for Cosmology - Lecture 21

Achim Kempf University of Waterloo

March 25, 2014

PIRSA:14030002
Far from equilibrium energy flow in quantum critical systems

March 25, 2014

PIRSA:14030089

High Energy Physics

We investigate far from equilibrium energy transport in strongly coupled quantum critical systems. Combining results from gauge-gravity duality, relativistic hydrodynamics, and quantum field theory, we argue that long-time energy transport after a local thermal quench occurs via a universal steady-state for any spatial dimensionality. This is described by a boosted thermal state. We determine the transport properties of this emergent steady state, including the average energy flow and its long-time fluctuations.
Naturalness and the Weak Gravity Conjecture

Clifford Cheung California Institute of Technology (Caltech) - Physics Office

March 25, 2014

PIRSA:14030119

High Energy Physics

The weak gravity conjecture (WGC) asserts a powerful consistency condition on gauge theories coupled to quantum gravity: an Abelian, long-range force requires a state of charge q and mass m such that q > m/mPl. Failure of this condition implies the existence of stable black hole remnants and is in tension with no-hair theorems. In this paper, we argue that the WGC creates a non- perturbative obstruction to naturalness, which is the notion that dimensionless coefficients should take on O(1) values in the absence of enhanced symmetry. As an illustration, we show that for scalar quantum electrodynamics, a natural spectrum can actually be forbidden by the WGC, which bounds a radiatively unstable quantity, m, by a radiatively stable quantity, q. More generally, the WGC can be at odds with naturalness in any theory containing charged fundamental scalars. We extend the conditions of the WGC to more complicated theories with multiple gauge symmetries and particles. Finally, we discuss implications for the hierarchy problem and construct a simple model in which the natural value of the electroweak scale—at the cutoff—is forbidden by the WGC.
13/14 PSI - Explorations in String Theory - Lecture 7

Andrei Starinets University of Oxford

March 25, 2014

PIRSA:14030067
Cosmic initial conditions and the CMB

Daniel Grin California Institute of Technology

March 25, 2014

PIRSA:14030112

Astrophysics

One new frontier in cosmology is the frequency spectrum of the CMB. Future instruments may be precise enough to measure deviations from the nearly-perfect blackbody, measuring a chemical potential and thus probing energy injection at extremely high redshift. I will discuss ($\mu$ and $y$-type) CMB spectral distortions from the dissipation of entropy (isocurvature)-sourced acoustic modes. I will then discuss how a high-energy phase transition could also source such distortions. I will then switch gears and talk about the possibility of measuring a spatial fluctuation in the baryon/DM ratio using the CMB, including recent observational results. I may also muse on the surprising possible connection between these compensated isocurvature modes and the anomalously low large-scale scalar power hinted at by Planck observations of the CMB temperature power spectrum and the recent claimed BICEP2 detection of primordial tensor modes

Title	Date	Collection	Type	Info
13/14 PSI - Explorations in Condensed Matter - Lecture 9	2014‑03‑27	13/14 PSI - Explorations in Condensed Matter	Course	View details
13/14 PSI - Explorations in Quantum Information - Lecture 9	2014‑03‑27	13/14 PSI - Explorations in Quantum Information	Course	View details
The invasion of physics by information theory	2014‑03‑26	Colloquium	Scientific Series	View details
13/14 PSI - Explorations in String Theory - Lecture 8	2014‑03‑26	13/14 PSI - Explorations in String Theory	Course	View details
GeV Gamma-Rays from the Central Milky Way and the Case for Annihilating Dark Matter	2014‑03‑26	Particle Physics	Scientific Series	View details
13/14 PSI - Explorations in Condensed Matter - Lecture 8	2014‑03‑26	13/14 PSI - Explorations in Condensed Matter	Course	View details
13/14 PSI - Explorations in Quantum Information - Lecture 8	2014‑03‑26	13/14 PSI - Explorations in Quantum Information	Course	View details
Introduction to Quantum Field Theory for Cosmology - Lecture 21	2014‑03‑25	Quantum Field Theory for Cosmology - 2014	Course	View details
Far from equilibrium energy flow in quantum critical systems	2014‑03‑25	Quantum Fields and Strings	Scientific Series	View details
Naturalness and the Weak Gravity Conjecture	2014‑03‑25	Particle Physics	Scientific Series	View details
13/14 PSI - Explorations in String Theory - Lecture 7	2014‑03‑25	13/14 PSI - Explorations in String Theory	Course	View details
Cosmic initial conditions and the CMB	2014‑03‑25	Cosmology and Gravitation	Scientific Series	View details

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Format results

13/14 PSI - Explorations in Condensed Matter - Lecture 9

13/14 PSI - Explorations in Quantum Information - Lecture 9

The invasion of physics by information theory

13/14 PSI - Explorations in String Theory - Lecture 8

GeV Gamma-Rays from the Central Milky Way and the Case for Annihilating Dark Matter

13/14 PSI - Explorations in Condensed Matter - Lecture 8

13/14 PSI - Explorations in Quantum Information - Lecture 8

Introduction to Quantum Field Theory for Cosmology - Lecture 21

Far from equilibrium energy flow in quantum critical systems

Naturalness and the Weak Gravity Conjecture

13/14 PSI - Explorations in String Theory - Lecture 7

Cosmic initial conditions and the CMB

13/14 PSI - Explorations in Condensed Matter - Lecture 9

13/14 PSI - Explorations in Quantum Information - Lecture 9

The invasion of physics by information theory

13/14 PSI - Explorations in String Theory - Lecture 8

GeV Gamma-Rays from the Central Milky Way and the Case for Annihilating Dark Matter

13/14 PSI - Explorations in Condensed Matter - Lecture 8

13/14 PSI - Explorations in Quantum Information - Lecture 8

Introduction to Quantum Field Theory for Cosmology - Lecture 21

Far from equilibrium energy flow in quantum critical systems

Naturalness and the Weak Gravity Conjecture

13/14 PSI - Explorations in String Theory - Lecture 7

Cosmic initial conditions and the CMB