Talks

9481 - 9492 of 16763 Results

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

Quantum Fields and Strings
Naturalness and the Weak Gravity Conjecture

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

March 25, 2014

PIRSA:14030119

Particle 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

Cosmology
13/14 PSI - Explorations in Condensed Matter - Lecture 7

Guifre Vidal Alphabet (United States)

March 25, 2014

PIRSA:14040030
13/14 PSI - Explorations in Quantum Information - Lecture 7

David Cory Institute for Quantum Computing (IQC)

March 25, 2014

PIRSA:14030037
13/14 PSI - Explorations in String Theory - Lecture 6

Andrei Starinets University of Oxford

March 24, 2014

PIRSA:14030066
13/14 PSI - Explorations in Condensed Matter - Lecture 6

Guifre Vidal Alphabet (United States)

March 24, 2014

PIRSA:14040029
13/14 PSI - Explorations in Quantum Information - Lecture 6

David Cory Institute for Quantum Computing (IQC)

March 24, 2014

PIRSA:14030036
13/14 PSI - Explorations in String Theory - Lecture 5

Andrei Starinets University of Oxford

March 21, 2014

PIRSA:14030063
Ambiguities in order-theoretic formulations of thermodynamics

Harvey Brown University of Oxford

March 21, 2014

PIRSA:14030093

Quantum Foundations

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

Quantum Fields and Strings

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

Particle 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

Cosmology

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
13/14 PSI - Explorations in Condensed Matter - Lecture 7

Guifre Vidal Alphabet (United States)

March 25, 2014

PIRSA:14040030
13/14 PSI - Explorations in Quantum Information - Lecture 7

David Cory Institute for Quantum Computing (IQC)

March 25, 2014

PIRSA:14030037
13/14 PSI - Explorations in String Theory - Lecture 6

Andrei Starinets University of Oxford

March 24, 2014

PIRSA:14030066
13/14 PSI - Explorations in Condensed Matter - Lecture 6

Guifre Vidal Alphabet (United States)

March 24, 2014

PIRSA:14040029
13/14 PSI - Explorations in Quantum Information - Lecture 6

David Cory Institute for Quantum Computing (IQC)

March 24, 2014

PIRSA:14030036
13/14 PSI - Explorations in String Theory - Lecture 5

Andrei Starinets University of Oxford

March 21, 2014

PIRSA:14030063
Ambiguities in order-theoretic formulations of thermodynamics

Harvey Brown University of Oxford

March 21, 2014

PIRSA:14030093

Quantum Foundations

Since the 1909 work of Carathéodory, an axiomatic approach to thermodynamics has gained ground which highlights the role of the the binary relation of adiabatic accessibility between equilibrium states. A feature of Carathédory's system is that the version therein of the second law contains an ambiguity about the nature of irreversible adiabatic processes, making it weaker than the traditional Kelvin-Planck statement of the law. This talk attempts first to clarify the nature of this ambiguity, by defining the arrow of time in thermodynamics by way of the Equilibrium Principle (``Minus First Law''). It then examines the extent to which the 1989 axiomatisation of Lieb and Yngvason shares the same ambiguity, despite proposing a very different approach to the second law.

Title	Date	Collection	Type	Info
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
13/14 PSI - Explorations in Condensed Matter - Lecture 7	2014‑03‑25	13/14 PSI - Explorations in Condensed Matter	Course	View details
13/14 PSI - Explorations in Quantum Information - Lecture 7	2014‑03‑25	13/14 PSI - Explorations in Quantum Information	Course	View details
13/14 PSI - Explorations in String Theory - Lecture 6	2014‑03‑24	13/14 PSI - Explorations in String Theory	Course	View details
13/14 PSI - Explorations in Condensed Matter - Lecture 6	2014‑03‑24	13/14 PSI - Explorations in Condensed Matter	Course	View details
13/14 PSI - Explorations in Quantum Information - Lecture 6	2014‑03‑24	13/14 PSI - Explorations in Quantum Information	Course	View details
13/14 PSI - Explorations in String Theory - Lecture 5	2014‑03‑21	13/14 PSI - Explorations in String Theory	Course	View details
Ambiguities in order-theoretic formulations of thermodynamics	2014‑03‑21	Quantum Foundations	Scientific Series	View details

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