Search Talks

Search results in General Relativity & Quantum Cosmology from PIRSA

1561 - 1572 of 1952 Results

12/13 PSI - Gravitational Physics Review Lecture 2

Ruth Gregory King's College London
January 29, 2013

PIRSA:13010094
General Relativity & Quantum Cosmology
12/13 PSI - Quantum Gravity Review Lecture 1

Bianca Dittrich Perimeter Institute for Theoretical Physics
January 28, 2013

PIRSA:13010089
General Relativity & Quantum Cosmology
12/13 PSI - Gravitational Physics Review Lecture 1

Ruth Gregory King's College London
January 28, 2013

PIRSA:13010093
General Relativity & Quantum Cosmology
What is motion? What is time?

Flavio Mercati University of Naples Federico II
January 23, 2013

PIRSA:13010003
General Relativity & Quantum Cosmology
The black hole information paradox and its resolution

Ted Jacobson University of Maryland, College Park
January 17, 2013

PIRSA:13010021
General Relativity & Quantum Cosmology
New transport properties of holographic superfluids

Daniel Fernandez University of Iceland
January 10, 2013

PIRSA:13010004
General Relativity & Quantum Cosmology
Black holes: To be or not be, that is the question

Luis Garay Complutense University of Madrid
December 13, 2012

PIRSA:12120032
General Relativity & Quantum Cosmology
Renormalizing TGFTs: a 3d example on SU(2)

Sylvain Carrozza University of Burgundy
December 06, 2012

PIRSA:12120007
General Relativity & Quantum Cosmology
Approaches to modeling pulsar magnetospheres

Anatoly Spitkovsky Princeton University
December 06, 2012

PIRSA:12120001
General Relativity & Quantum Cosmology
Mass and Tension (momentum) Sum Rules in AdS (dS)

Jennie Traschen University of Massachusetts Amherst
November 27, 2012

PIRSA:12110042
General Relativity & Quantum Cosmology
Dynamical Capture Compact Binary Mergers

William East Perimeter Institute for Theoretical Physics
November 22, 2012

PIRSA:12110054
General Relativity & Quantum Cosmology
Canonical tensor models with local time

Naoki Sasakura Yukawa Institute for Theoretical Physics
November 15, 2012

PIRSA:12110065
General Relativity & Quantum Cosmology

12/13 PSI - Gravitational Physics Review Lecture 2

Ruth Gregory King's College London
January 29, 2013

PIRSA:13010094
General Relativity & Quantum Cosmology
12/13 PSI - Quantum Gravity Review Lecture 1

Bianca Dittrich Perimeter Institute for Theoretical Physics
January 28, 2013

PIRSA:13010089
General Relativity & Quantum Cosmology
12/13 PSI - Gravitational Physics Review Lecture 1

Ruth Gregory King's College London
January 28, 2013

PIRSA:13010093
General Relativity & Quantum Cosmology
What is motion? What is time?

Flavio Mercati University of Naples Federico II
January 23, 2013

PIRSA:13010003
General Relativity & Quantum Cosmology
I give an account of the Machian approach to dynamics, from Mach's critique of Newton to the work of Barbour, Bertotti, York and O'Murchadha, which culminated in the theory of Shape Dynamics, a new and original way of thinking about General Relativity. I conclude commenting on the present research lines in Shape Dynamics, and the opportunity it offers to solve the problem of time in quantum gravity.

Support for this colloquium is provided by The Templeton Frontiers Program.
The black hole information paradox and its resolution

Ted Jacobson University of Maryland, College Park
January 17, 2013

PIRSA:13010021
General Relativity & Quantum Cosmology
Both AdS/CFT duality and more general reasoning from quantum gravity point to a rich collection of boundary observables that always evolve unitarily. The physical quantum gravity states described by these observables must be solutions of the spatial diffeomorphism and Wheeler-deWitt constraints, which implies that the state space does not factorize into a tensor product of localized degrees of freedom. The "firewall" argument that unitarity of black hole evaporation is incompatible with a regular near horizon region is based on such a factorization, hence is not applicable in quantum gravity. A version of black hole complementarity resolves the apparent conflict. (I will also discuss doubts and questions.)
New transport properties of holographic superfluids

Daniel Fernandez University of Iceland
January 10, 2013

PIRSA:13010004
General Relativity & Quantum Cosmology
In the context of holography applied to condensed matter theory, I will present an analysis of transport properties of p-wave superfluids by means of a gravity dual. Fluctuations modes in the SU(2) Einstein-Yang-Mills theory are considered, and phenomenological implications are derived. Due to the spatial anisotropy of the system, a non-universal shear viscosity is obtained, along with a new coefficient associated to normal stress differences. I will also discuss how the transport phenomena in this model is related to the thermoelectric, flexoelectric and piezoelectric effects (mixing of electric current, heat flux and mechanical stress), which have been observed in some superconductors and crystal liquids.
Black holes: To be or not be, that is the question

Luis Garay Complutense University of Madrid
December 13, 2012

PIRSA:12120032
General Relativity & Quantum Cosmology
I will review some problems of the black hole paradigm and explore other
possibilities for the final state of stellar collapse other than an evaporating
black hole. In particular I will use the so-called transplanckian problem as a
guide in this search for a compelling scenario for the evaporation of
ultracompact objects.
Renormalizing TGFTs: a 3d example on SU(2)

Sylvain Carrozza University of Burgundy
December 06, 2012

PIRSA:12120007
General Relativity & Quantum Cosmology
I will recall the main motivations for considering spin foam models in their Group Field Theory (GFT) versions, which are quantum field theories defined on group manifolds. As for any other quantum field theory, a fully consistent definition of the latter must involve renormalization. I will briefly review a specific class of GFTs, called tensorial, for which progress in this direction has recently been possible. A new just-renormalizable model, in three dimensions and on the SU(2) group, will be presented. Interestingly, it includes the geometric constraint of the Boulatov model, and might as such be related to Euclidean quantum gravity in three dimensions. Furthermore, this opens the way to a similar analysis of current 4d gravity spin foam models.
Approaches to modeling pulsar magnetospheres

Anatoly Spitkovsky Princeton University
December 06, 2012

PIRSA:12120001
General Relativity & Quantum Cosmology
Pulsars are rotating magnetized neutron stars that emit broadband pulses of radiation. Our ability to model magnetospheres of pulsars has been hampered by the difficulty of solving the self-consistent behavior of strongly magnetized relativistic plasmas. I will describe
recent progress in numerical modeling of magnetically-dominated plasmas and show applications to pulsar magnetospheres in increasing levels of realism, including ideal and resistive force-free,
relativistic MHD and kinetic models. The knowledge of the magnetospheric shape together with the new observations of gamma-ray emission from pulsars with Fermi telescope allow to directly constrain the location and physics of the acceleration regions in the magnetosphere and the origin of high energy emission. The pulsar magnetosphere is a prototype for other strongly magnetized
astrophysical objects, and I will discuss how the lessons from pulsar modeling can be useful in predicting EM counterparts to gravitational wave sources.
Mass and Tension (momentum) Sum Rules in AdS (dS)

Jennie Traschen University of Massachusetts Amherst
November 27, 2012

PIRSA:12110042
General Relativity & Quantum Cosmology
The stress-energy tensor in a conformal field theory has zero trace. Hence AdS boundary stress-tensors are traceless by construction, to match this property of the dual CFT. An elegant (aka nifty) construction based on the conformal isometry of AdS will be presented which shows that in an asymptotically AdS spacetime, the sum of the ADM mass and the ADM tensions is zero. This result follows strictly from the gravitational point of view- that is, the Einstein equations and the definitions of the ADM charges. Further, it turns out that perturbative stress-energy sources in an asymptotically AdS spacetime must satisfy a local version of this constraint, namely that the sum of the energy density minus the pressures equals zero. The situation with positive cosmological constant is both similar and distinct in interesting ways, which will be briefly discussed. The analogous (analytically continued) conformal isometry in dS is the root of the ``k^4 “ power spectrum for causal cosmological perturbations. Work in progress (speculations) will be presented about a corresponding sum-rule for gravitational charges defined at future infinity in a spacetime that approaches dS at late times.
Dynamical Capture Compact Binary Mergers

William East Perimeter Institute for Theoretical Physics
November 22, 2012

PIRSA:12110054
General Relativity & Quantum Cosmology
Canonical tensor models with local time

Naoki Sasakura Yukawa Institute for Theoretical Physics
November 15, 2012

PIRSA:12110065
General Relativity & Quantum Cosmology
Tensor models are generalization of matrix models, and are studied as discrete models for quantum gravity for more than two-dimensions. Among them, the rank-three tensor models can be interpreted as theories of dynamical fuzzy spaces, and they generally have the feature of
respecting symmetries. In this talk, after briefly reviewing some results on Euclidean models such as spontaneous generation of fuzzy spaces and Euclidean general relativity respecting the diffeomorphism symmetry on them, I will present a way to introduce “local” time to the rank-three tensor models by constructing “local” Hamiltonians. The consistency among the multiple ways of local time evolutions is guaranteed by the on-shell closure of the constraint algebra among the
local Hamiltonians and the symmetry generators of the tensor models. The constraint algebra is shown to approach the DeWitt algebra in a formal continuum limit. I will also discuss the two-fold uniqueness of the local Hamiltonians, and will briefly show some preliminary results on the quantization.

Title	Date	Collection	Type	Info
12/13 PSI - Gravitational Physics Review Lecture 2	2013‑01‑29	12/13 PSI - Gravitational Physics Review	Course	View details
12/13 PSI - Quantum Gravity Review Lecture 1	2013‑01‑28	12/13 PSI - Quantum Gravity Review	Course	View details
12/13 PSI - Gravitational Physics Review Lecture 1	2013‑01‑28	12/13 PSI - Gravitational Physics Review	Course	View details
What is motion? What is time?	2013‑01‑23	Colloquium	Scientific Series	View details
The black hole information paradox and its resolution	2013‑01‑17	Quantum Gravity	Scientific Series	View details
New transport properties of holographic superfluids	2013‑01‑10	Strong Gravity	Scientific Series	View details
Black holes: To be or not be, that is the question	2012‑12‑13	Quantum Gravity	Scientific Series	View details
Renormalizing TGFTs: a 3d example on SU(2)	2012‑12‑06	Quantum Gravity	Scientific Series	View details
Approaches to modeling pulsar magnetospheres	2012‑12‑06	Strong Gravity	Scientific Series	View details
Mass and Tension (momentum) Sum Rules in AdS (dS)	2012‑11‑27	Cosmology and Gravitation	Scientific Series	View details
Dynamical Capture Compact Binary Mergers	2012‑11‑22	Strong Gravity	Scientific Series	View details
Canonical tensor models with local time	2012‑11‑15	Quantum Gravity	Scientific Series	View details

Supported by

Format results

12/13 PSI - Gravitational Physics Review Lecture 2

12/13 PSI - Quantum Gravity Review Lecture 1

12/13 PSI - Gravitational Physics Review Lecture 1

What is motion? What is time?

The black hole information paradox and its resolution

New transport properties of holographic superfluids

Black holes: To be or not be, that is the question

Renormalizing TGFTs: a 3d example on SU(2)

Approaches to modeling pulsar magnetospheres

Mass and Tension (momentum) Sum Rules in AdS (dS)

Dynamical Capture Compact Binary Mergers

Canonical tensor models with local time

12/13 PSI - Gravitational Physics Review Lecture 2

12/13 PSI - Quantum Gravity Review Lecture 1

12/13 PSI - Gravitational Physics Review Lecture 1

What is motion? What is time?

The black hole information paradox and its resolution

New transport properties of holographic superfluids

Black holes: To be or not be, that is the question

Renormalizing TGFTs: a 3d example on SU(2)

Approaches to modeling pulsar magnetospheres

Mass and Tension (momentum) Sum Rules in AdS (dS)

Dynamical Capture Compact Binary Mergers

Canonical tensor models with local time