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Classical Space Times from S Matrices

Ira Rothstein Carnegie Mellon University
November 26, 2013

PIRSA:13110053
Particle Physics
BiGravity: from Cosmological Solutions to Dual Galileons

Matteo Fasiello University of Portsmouth
November 26, 2013

PIRSA:13110093
Cosmology
13/14 PSI - Condensed Matter - Lecture 12
- Anushya Chandran Perimeter Institute for Theoretical Physics
- Roger Melko University of Waterloo
- Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics
November 26, 2013

PIRSA:13110042
13/14 PSI - Quantum Field Theory II - Lecture 12

Francois David CEA Saclay

November 26, 2013

PIRSA:13110023
13/14 PSI - Condensed Matter - Lecture 11
- Anushya Chandran Perimeter Institute for Theoretical Physics
- Roger Melko University of Waterloo
- Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics
November 25, 2013

PIRSA:13110041
13/14 PSI - Quantum Field Theory II - Lecture 11

Francois David CEA Saclay

November 25, 2013

PIRSA:13110022
13/14 PSI - Condensed Matter - Lecture 10
- Anushya Chandran Perimeter Institute for Theoretical Physics
- Roger Melko University of Waterloo
- Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics
November 22, 2013

PIRSA:13110038
13/14 PSI - Quantum Field Theory II - Lecture 10

Francois David CEA Saclay

November 22, 2013

PIRSA:13110019
General Relativity for Cosmology - Lecture 20

Achim Kempf University of Waterloo

November 21, 2013

PIRSA:13110006
General Relativity for Cosmology - Lecture 19

Achim Kempf University of Waterloo

November 21, 2013

PIRSA:13110002
Dimensional reduction in the sky
November 21, 2013

PIRSA:13110059
Quantum Gravity
Charged particle motion in magnetized black holes

Valeri Frolov University of Alberta
November 21, 2013

PIRSA:13110066
Strong Gravity

Classical Space Times from S Matrices

Ira Rothstein Carnegie Mellon University
November 26, 2013

PIRSA:13110053
Particle Physics
Progress in calculating S matrix elements have shown that the malicious redundancies in non-linear gauge theories can be circumvented by utilizing unitarity methods in conjunction with BCFW recursion relations. When calculating in this fashion all of the interaction vertices beyond the three point function can be ignored. This simplification is especially useful in gravity which contains an infinite number of such non-linear interactions. It is natural to ask whether off-shell quantities, such as classical solutions, can also be generated using only the three point vertex. In this talk I will show that this is indeed the case by extracting classical solutions to GR from on-hell two to two scattering S-matrix elements. In so doing we will completely circumvent the action as well as the equations of motion. The only inputs will be Lorentz invariance, the existence of a massless spin-two particle and locality. Because of the double copy relation this implies there exists, a yet to be understood, connection between solutions to Yang-Mills theory and Gravity. I will also discuss how this technique can be used to simplify calculations of higher order post-Newtonian corrections to gravitational potentials relevant to the problem of binary inspirals.
BiGravity: from Cosmological Solutions to Dual Galileons

Matteo Fasiello University of Portsmouth
November 26, 2013

PIRSA:13110093
Cosmology
I will present Cosmological FRW Solutions in BiGravity Theories and discuss their stability. After deriving the stability bound, one realizes that in Bigravity (in contradistinction to the FRW massive gravity case) the tension between requirements stemming from stability and those set by observations is resolved. The stability bound can also be derived in the decoupling limit of Bigravity. In this context an intriguing duality between Galilean interactions has emerged.
13/14 PSI - Condensed Matter - Lecture 12
- Anushya Chandran Perimeter Institute for Theoretical Physics
- Roger Melko University of Waterloo
- Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics
November 26, 2013

PIRSA:13110042
13/14 PSI - Quantum Field Theory II - Lecture 12

Francois David CEA Saclay

November 26, 2013

PIRSA:13110023
13/14 PSI - Condensed Matter - Lecture 11
- Anushya Chandran Perimeter Institute for Theoretical Physics
- Roger Melko University of Waterloo
- Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics
November 25, 2013

PIRSA:13110041
13/14 PSI - Quantum Field Theory II - Lecture 11

Francois David CEA Saclay

November 25, 2013

PIRSA:13110022
13/14 PSI - Condensed Matter - Lecture 10
- Anushya Chandran Perimeter Institute for Theoretical Physics
- Roger Melko University of Waterloo
- Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics
November 22, 2013

PIRSA:13110038
13/14 PSI - Quantum Field Theory II - Lecture 10

Francois David CEA Saclay

November 22, 2013

PIRSA:13110019
General Relativity for Cosmology - Lecture 20

Achim Kempf University of Waterloo

November 21, 2013

PIRSA:13110006
General Relativity for Cosmology - Lecture 19

Achim Kempf University of Waterloo

November 21, 2013

PIRSA:13110002
Dimensional reduction in the sky
November 21, 2013

PIRSA:13110059
Quantum Gravity
In several approaches to quantum-gravity, the spectral dimension of spacetime runs from the standard value of 4 in the infrared (IR) to a smaller value in the ultraviolet (UV). Describing this running in terms of deformed dispersion relations, I show that a striking cosmological implication is that that UV behavior leading to 2 spectral dimensions results in an exactly scale-invariant spectrum of vacuum scalar and tensor fluctuations. I discuss scenarios that break exact scale-invariance and show that the tensor to scalar ratio is fixed by the UV ratio between the speed of gravity and the speed of light. Cosmological perturbations in this framework display a wavelength-dependent speed of light, but by transforming to a suitable "rainbow frame" this feature can be removed, at the expense of modifying gravity. In particular it turns out that the following concepts are closely connected: scale-invariance of vacuum fluctuations, conformal invariance of the gravitational coupling, UV reduction to spectral dimension 2 in position space and UV reduction to Hausdorff dimension 2 in energy-momentum space.
Charged particle motion in magnetized black holes

Valeri Frolov University of Alberta
November 21, 2013

PIRSA:13110066
Strong Gravity
There exist evidences that magnetic field in the vicinity of astrophysical black holes plays an important role. In particular it is required for explanation of such phenomenon as jet formation. Study of such problems in all their complexity requires 3D numerical simulations of the magnetohydrodynamics in a strong gravitational field. Quite often when dealing with such a complicated problem it is instructive to consider first its simplifications, which can be treated either analytically, or by integrating ordinary differential equations. Motion of a charged particle in a weakly magnetized black hole is an important example. We consider a non-rotating black hole in the weak magnetic field which is homogeneous at infinity. In the talk I discuss the following problems: How does such a magnetic field affect charged particle motion in the equatorial plane? How does it change the radius of the innermost stable circular orbits (ISCO) and period of rotation? I shall demonstratethat the magnetic field increases the efficiency of the energy extraction from the black hole and that magnetized black holes can be used as "particle accelerators". Finally, I shall discuss out-of-equatorial-plane motion and demonstrate that it is chaotic. Possible applications of these results to astrophysics are briefly discussed.

Title	Date	Collection	Type	Info
Classical Space Times from S Matrices	2013‑11‑26	Particle Physics	Scientific Series	View details
BiGravity: from Cosmological Solutions to Dual Galileons	2013‑11‑26	Cosmology and Gravitation	Scientific Series	View details
13/14 PSI - Condensed Matter - Lecture 12	2013‑11‑26	13/14 PSI - Condensed Matter	Course	View details
13/14 PSI - Quantum Field Theory II - Lecture 12	2013‑11‑26	13/14 PSI - Quantum Field Theory II	Course	View details
13/14 PSI - Condensed Matter - Lecture 11	2013‑11‑25	13/14 PSI - Condensed Matter	Course	View details
13/14 PSI - Quantum Field Theory II - Lecture 11	2013‑11‑25	13/14 PSI - Quantum Field Theory II	Course	View details
13/14 PSI - Condensed Matter - Lecture 10	2013‑11‑22	13/14 PSI - Condensed Matter	Course	View details
13/14 PSI - Quantum Field Theory II - Lecture 10	2013‑11‑22	13/14 PSI - Quantum Field Theory II	Course	View details
General Relativity for Cosmology - Lecture 20	2013‑11‑21	General Relativity for Cosmology - 2013	Course	View details
General Relativity for Cosmology - Lecture 19	2013‑11‑21	General Relativity for Cosmology - 2013	Course	View details
Dimensional reduction in the sky	2013‑11‑21	Quantum Gravity	Scientific Series	View details
Charged particle motion in magnetized black holes	2013‑11‑21	Strong Gravity	Scientific Series	View details

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