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14/15 PSI - Quantum Field Theory I (A) - Lecture 11
- Tibra Ali Perimeter Institute for Theoretical Physics
- Dan Wohns Perimeter Institute for Theoretical Physics
October 21, 2014

PIRSA:14100042
14/15 PSI - Conformal Field Theory - Lecture 10

Freddy Cachazo Perimeter Institute for Theoretical Physics

October 20, 2014

PIRSA:14100022
14/15 PSI - Statistical Mechanics - Lecture 10

Anton Burkov University of Waterloo

October 20, 2014

PIRSA:14100098
14/15 PSI - Quantum Field Theory I (A) - Lecture 10
- Tibra Ali Perimeter Institute for Theoretical Physics
- Dan Wohns Perimeter Institute for Theoretical Physics
October 20, 2014

PIRSA:14100041
14/15 PSI - Conformal Field Theory - Lecture 9

Pedro Vieira Perimeter Institute for Theoretical Physics

October 17, 2014

PIRSA:14100019
14/15 PSI - Quantum Field Theory I (A) - Lecture 9
- Tibra Ali Perimeter Institute for Theoretical Physics
- Dan Wohns Perimeter Institute for Theoretical Physics
October 17, 2014

PIRSA:14100038
14/15 PSI - Statistical Mechanics - Lecture 9

Anton Burkov University of Waterloo

October 17, 2014

PIRSA:14100095
14/15 PSI - Quantum Field Theory I (A) - Lecture 8
- Tibra Ali Perimeter Institute for Theoretical Physics
- Dan Wohns Perimeter Institute for Theoretical Physics
October 16, 2014

PIRSA:14100037
14/15 PSI - Conformal Field Theory - Lecture 8

Pedro Vieira Perimeter Institute for Theoretical Physics

October 16, 2014

PIRSA:14100018
Is B-Mode Polarization of the CMB the Holy Grail of Inflation?

Robert Brandenberger McGill University - Department of Physics
October 16, 2014

PIRSA:14100002
Quantum Gravity
Spinning Black Holes and the Membrane Paradigm

Robert Penna Massachusetts Institute of Technology (MIT)
October 16, 2014

PIRSA:14100007
Strong Gravity
Cosmological Constraints on theories of Modified Gravity

Alexandre Barreira Durham University
October 16, 2014

PIRSA:14100074
Cosmology

14/15 PSI - Quantum Field Theory I (A) - Lecture 11
- Tibra Ali Perimeter Institute for Theoretical Physics
- Dan Wohns Perimeter Institute for Theoretical Physics
October 21, 2014

PIRSA:14100042
14/15 PSI - Conformal Field Theory - Lecture 10

Freddy Cachazo Perimeter Institute for Theoretical Physics

October 20, 2014

PIRSA:14100022
14/15 PSI - Statistical Mechanics - Lecture 10

Anton Burkov University of Waterloo

October 20, 2014

PIRSA:14100098
14/15 PSI - Quantum Field Theory I (A) - Lecture 10
- Tibra Ali Perimeter Institute for Theoretical Physics
- Dan Wohns Perimeter Institute for Theoretical Physics
October 20, 2014

PIRSA:14100041
14/15 PSI - Conformal Field Theory - Lecture 9

Pedro Vieira Perimeter Institute for Theoretical Physics

October 17, 2014

PIRSA:14100019
14/15 PSI - Quantum Field Theory I (A) - Lecture 9
- Tibra Ali Perimeter Institute for Theoretical Physics
- Dan Wohns Perimeter Institute for Theoretical Physics
October 17, 2014

PIRSA:14100038
14/15 PSI - Statistical Mechanics - Lecture 9

Anton Burkov University of Waterloo

October 17, 2014

PIRSA:14100095
14/15 PSI - Quantum Field Theory I (A) - Lecture 8
- Tibra Ali Perimeter Institute for Theoretical Physics
- Dan Wohns Perimeter Institute for Theoretical Physics
October 16, 2014

PIRSA:14100037
14/15 PSI - Conformal Field Theory - Lecture 8

Pedro Vieira Perimeter Institute for Theoretical Physics

October 16, 2014

PIRSA:14100018
Is B-Mode Polarization of the CMB the Holy Grail of Inflation?

Robert Brandenberger McGill University - Department of Physics
October 16, 2014

PIRSA:14100002
Quantum Gravity
I will discuss why the search for B-Mode Polarization of the Cosmic Microwave Background (CMB) is very important for early universe cosmology, but that a discovery of such a polarization mode is in no way a confirmation of inflationary cosmology.
Spinning Black Holes and the Membrane Paradigm

Robert Penna Massachusetts Institute of Technology (MIT)
October 16, 2014

PIRSA:14100007
Strong Gravity
There are about nine astrophysical black holes with measurements of the black hole's spin via the continuum fitting method. Several of these black holes drive powerful jets, which appear to extract the black hole's rotational energy. I will discuss the theory behind these observations, with a particular focus on the black hole membrane paradigm. The membrane paradigm is useful on a practical level for understanding black hole jets. However, it may also be related to fundamental physics through holography and AdS/CFT. This suggests new opportunities for interactions between fundamental physics and astrophysics.
Cosmological Constraints on theories of Modified Gravity

Alexandre Barreira Durham University
October 16, 2014

PIRSA:14100074
Cosmology
Recently, research in cosmology has seen a growing interest in theories of gravity beyond General Relativity (GR). From an observational point of view, there are two main reasons for this. Firstly, the law of gravity has never been directly tested on scales larger than the Solar System. Hence, by understanding better the various signatures that different gravity models can leave on cosmological observables, one can improve the chances of identifying any departures from GR, or alternatively, extend the model's observational success into a whole new regime. Secondly, theories of modified gravity can arise also as an alternative to the cosmological constant (or any other form of dark energy) to explain the current accelerated expansion of the Universe. Using my results from suitably modified Boltzmann, N-body codes and semi-analytical models of structure formation, I will describe the way modified gravity models typically impact a series of cosmological observables. I will use two popular models as examples, which are known as Galileon and Nonlocal Gravity. In the Galileon model, the modifications to gravity on large scales are driven by nonlinear derivative interactions of a scalar field, which can nevertheless be suppressed in the Solar System by means of a mechanism known as Vainshtein screening. This model can provide a good fit to the latest CMB, BAO and SNIa data, although with different cosmological parameters than the standard LCDM model. Specifically, unlike LCDM, the Galileon model predicts nonzero neutrino masses (over 5sigma) and the constraints on the Hubble rate are compatible with its local determinations. The results from my N-body simulations and Halo Occupation Distribution analysis also show that the model can describe the measured clustering amplitude of Luminous Red Galaxies and that the screening mechanism can be very efficient in "hiding" the modifications to gravity on small scales. However, these results also show that the observational viability of the model may be under pressure due to the combined constraints derived from the sign of the ISW effect and from Solar System tests. In the Nonlocal model, the acceleration of the universe is driven by terms that involve the inverse of a derivative operator acting on curvature tensors. This model is also likely to pass large-scale structure constraints with the same flying colors as Galileon gravity, but the lack of a screening mechanism in this model makes it unclear on whether or not it is able to satisfy Solar System constraints. These steps I will describe for the cases of the Galileon and Nonlocal models can be viewed as guidelines for one to place constraints on other (or not yet invented) models of modified gravity. References: The results I will describe are based on the following papers: arXiv:1208.0600, arXiv:1302.6241, arXiv:1306.3219, arXiv:1308.3699, arXiv:1401.1497, arXiv:1404.1365, arXiv:1406.0485, arXiv:1408.1084

Title	Date	Collection	Type	Info
14/15 PSI - Quantum Field Theory I (A) - Lecture 11	2014‑10‑21	14/15 PSI - Quantum Field Theory	Course	View details
14/15 PSI - Conformal Field Theory - Lecture 10	2014‑10‑20	14/15 PSI - Conformal Field Theory	Course	View details
14/15 PSI - Statistical Mechanics - Lecture 10	2014‑10‑20	14/15 PSI - Statistical Mechanics	Course	View details
14/15 PSI - Quantum Field Theory I (A) - Lecture 10	2014‑10‑20	14/15 PSI - Quantum Field Theory	Course	View details
14/15 PSI - Conformal Field Theory - Lecture 9	2014‑10‑17	14/15 PSI - Conformal Field Theory	Course	View details
14/15 PSI - Quantum Field Theory I (A) - Lecture 9	2014‑10‑17	14/15 PSI - Quantum Field Theory	Course	View details
14/15 PSI - Statistical Mechanics - Lecture 9	2014‑10‑17	14/15 PSI - Statistical Mechanics	Course	View details
14/15 PSI - Quantum Field Theory I (A) - Lecture 8	2014‑10‑16	14/15 PSI - Quantum Field Theory	Course	View details
14/15 PSI - Conformal Field Theory - Lecture 8	2014‑10‑16	14/15 PSI - Conformal Field Theory	Course	View details
Is B-Mode Polarization of the CMB the Holy Grail of Inflation?	2014‑10‑16	Quantum Gravity		View details
Spinning Black Holes and the Membrane Paradigm	2014‑10‑16	Strong Gravity	Scientific Series	View details
Cosmological Constraints on theories of Modified Gravity	2014‑10‑16	Cosmology and Gravitation	Scientific Series	View details

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