Search Talks

Search results from PIRSA

10441 - 10452 of 16715 Results

The Effective Field Theory of Large Scale Structures

Enrico Pajer Utrecht University
March 19, 2013

PIRSA:13030110
Astrophysics
12/13 PSI - Explorations in Particle Theory Lecture 2

David Morrissey TRIUMF
March 19, 2013

PIRSA:13030066
High Energy Physics
12/13 PSI - Explorations on Quantum Information Lecture 2

David Cory Institute for Quantum Computing (IQC)
March 19, 2013

PIRSA:13030055
Quantum Physics
12/13 PSI - Explorations in Particle Theory Lecture 1

David Morrissey TRIUMF
March 18, 2013

PIRSA:13030065
High Energy Physics
12/13 PSI - Explorations on Quantum Information Lecture 1

David Cory Institute for Quantum Computing (IQC)
March 18, 2013

PIRSA:13030054
Quantum Physics
Advanced General Relativity - Lecture 16

Rafael Sorkin Perimeter Institute for Theoretical Physics

March 14, 2013

PIRSA:13030015
A CDT Hamiltonian from Horava-Lifshitz gravity

Yuki Sato Nagoya University
March 14, 2013

PIRSA:13030091
General Relativity & Quantum Cosmology
The dynamics of asymptotically anti-de Sitter spacetimes

Claude Warnick
March 14, 2013

PIRSA:13030077
General Relativity & Quantum Cosmology
The Higgs confronts 3 universes at the LHC

Markus Luty University of California, Davis
March 13, 2013

PIRSA:13030095
High Energy Physics
Advanced General Relativity - Lecture 15

Rafael Sorkin Perimeter Institute for Theoretical Physics

March 12, 2013

PIRSA:13030013
Neorealism and the Internal Language of Topoi

Sander Wolters Radboud Universiteit Nijmegen
March 12, 2013

PIRSA:13030107
Quantum Physics
Large N Chern-Simons-matter theories and three dimensional bosonization

Ofer Aharony Weizmann Institute of Science
March 12, 2013

PIRSA:13030106
High Energy Physics

The Effective Field Theory of Large Scale Structures

Enrico Pajer Utrecht University
March 19, 2013

PIRSA:13030110
Astrophysics
An analytical understanding of large-scale matter inhomogeneities is an important cornerstone of our cosmological model and helps us interpreting current and future data. The standard approach, namely Eulerian perturbation theory, is unsatisfactory for at least three reasons: there is no clear expansion parameter since the density contrast is not small everywhere; it does not consistently account for deviations at large scales from a perfect pressureless fluid induced by short-scale non-linearities; for generic initial conditions, loop corrections are UV divergent, making predictions cutoff dependent and hence unphysical. I will present the systematic construction of an Effective Field Theory of Large Scale Structures and show that it successfully addresses all of the above issues. The idea is to smooth the density and velocity fields on a scale larger than the non-linear scale. The resulting smoothed fields are then small everywhere and provide a well-defined small parameter for perturbation theory. Smoothing amounts to integrating out the short scales, whose non-linear dynamics is hard to describe analytically. Their effects on the large scales are then determined by the symmetries of the problems. They introduce additional terms in the fluid equations such as an effective pressure, dissipation and stochastic noise. These terms have exactly the right scale dependence to cancel all divergences at one loop, and this should hold at all loops.
I will present a clean example of the renormalization of the theory in an Einstein de Sitter universe with self-similar initial conditions and discuss the relative importance of loop and effective corrections.
12/13 PSI - Explorations in Particle Theory Lecture 2

David Morrissey TRIUMF
March 19, 2013

PIRSA:13030066
High Energy Physics
12/13 PSI - Explorations on Quantum Information Lecture 2

David Cory Institute for Quantum Computing (IQC)
March 19, 2013

PIRSA:13030055
Quantum Physics
12/13 PSI - Explorations in Particle Theory Lecture 1

David Morrissey TRIUMF
March 18, 2013

PIRSA:13030065
High Energy Physics
12/13 PSI - Explorations on Quantum Information Lecture 1

David Cory Institute for Quantum Computing (IQC)
March 18, 2013

PIRSA:13030054
Quantum Physics
Advanced General Relativity - Lecture 16

Rafael Sorkin Perimeter Institute for Theoretical Physics

March 14, 2013

PIRSA:13030015
A CDT Hamiltonian from Horava-Lifshitz gravity

Yuki Sato Nagoya University
March 14, 2013

PIRSA:13030091
General Relativity & Quantum Cosmology
Causal Dynamical Triangulations” (CDT) is a lattice theory where aspects of quantum gravity can be studied. Two-dimensional CDT can be solved analytically and the continuum (quantum) Hamiltonian obtained.
In this talk I will show that this continuum Hamiltonian is the one obtained by quantizing two-dimensional projectable Horava-Lifshitz gravity.
The dynamics of asymptotically anti-de Sitter spacetimes

Claude Warnick
March 14, 2013

PIRSA:13030077
General Relativity & Quantum Cosmology
The majority of work on asymptotically anti-de Sitter spacetimes, much of it motivated by the AdS/CFT correspondence, assumes configurations which are either at or close to equilibrium. Recently it has been discovered that genuinely dynamical spacetimes with AdS asymptotics can exhibit some surprising behaviour. In particular, numerical studies suggest AdS is dynamically unstable. I will discuss recent analytical (in)stability results for asymptotically AdS spacetimes, in particular how stability can be affected by boundary conditions at the timelike conformal infinity.
The Higgs confronts 3 universes at the LHC

Markus Luty University of California, Davis
March 13, 2013

PIRSA:13030095
High Energy Physics
The recent discovery of the Higgs boson is a fundamental advance in particle physics. This talk gives a theorist's perspective of the significance of this discovery. The Higgs boson was proposed in the 1960s, but it is best understood in the context of the quest to understand the weak interactions, which began with Fermi's theory of weak interactions almost 80 years ago. This has led to three very different paradigms for the structure of fundamental interactions at the TeV scale: supersymmetry, compositeness/extra dimensions, and anthropic selection. The Large Hadron Collider is the experimentum crucis for deciding between these different possible universes, and the discovery of the Higgs is a crucial clue. This talk will describe these paradigms, the implications of the Higgs discovery for them, and the outlook for further discoveries that would decide between them.
Advanced General Relativity - Lecture 15

Rafael Sorkin Perimeter Institute for Theoretical Physics

March 12, 2013

PIRSA:13030013
Neorealism and the Internal Language of Topoi

Sander Wolters Radboud Universiteit Nijmegen
March 12, 2013

PIRSA:13030107
Quantum Physics
Crudely formulated, the idea of neorealism, in the way that Chris Isham and Andreas Doering use it, means that each theory of physics, in its mathematical formulation should share certain structural properties of classical physics. These properties are chosen to allow some degree of realism in the interpretation (for example, physical variables always have values). Apart from restricting the form of physical theories, neorealism does increase freedom in the shape of physical theories in another way. Theories of physics may be interpreted in other topoi than the category of sets and functions. In my talk I will concentrate on two topos models for quantum theory. The contravariant model of Butterfield, Isham and Doering on the one hand, and the covariant model of Heunen, Landsman and Spitters on the other. I will argue that when we think of the topoi as generalized categories of sets (i.e. when we use the internal perspective of the topoi at hand), these two models are closely related, and both resemble classical physics. I will assume no background knowledge in topos theory.
Large N Chern-Simons-matter theories and three dimensional bosonization

Ofer Aharony Weizmann Institute of Science
March 12, 2013

PIRSA:13030106
High Energy Physics
I will discuss the conformal theories of N complex scalars or fermions in 2+1 dimensions, coupled to a U(N) Chern-Simons (CS) theory at level k. In the large N limit these theories have a high-spin symmetry, and, as I will review, they are dual to Vasiliev's high-spin gravity theories on four dimensional anti-de Sitter space. Maldacena and Zhiboedov showed that the high-spin symmetry determines the 2-point and 3-point functions of these theories at large N, up to two parameters. The duality to Vasiliev's gravity suggests that there is some mapping between the CS+scalar and CS+fermion theories (when one adds a quartic coupling to the scalar theories, to flow to their "critical fixed point"). We compute explicitly the large N limit of some 2-point and 3-point functions in these theories. We show that the results match with the general results of Maldacena and Zhiboedov, and they are consistent with an equivalence between the critical theory of N scalars coupled to a U(N) CS theory at level k, and the theory of k fermions coupled to a U(k) CS theory at level (N-1/2). We conjecture that this large N equivalence may be an exact duality between the scalar and fermion theories also at finite N, thus providing a bosonization of the fermionic theory. Similar results hold for real scalars (fermions) when U(N) is replaced by O(N).

Title	Date	Collection	Type	Info
The Effective Field Theory of Large Scale Structures	2013‑03‑19	Cosmology and Gravitation	Scientific Series	View details
12/13 PSI - Explorations in Particle Theory Lecture 2	2013‑03‑19	12/13 PSI - Explorations in Particle Theory	Course	View details
12/13 PSI - Explorations on Quantum Information Lecture 2	2013‑03‑19	12/13 PSI - Explorations on Quantum Information	Course	View details
12/13 PSI - Explorations in Particle Theory Lecture 1	2013‑03‑18	12/13 PSI - Explorations in Particle Theory	Course	View details
12/13 PSI - Explorations on Quantum Information Lecture 1	2013‑03‑18	12/13 PSI - Explorations on Quantum Information	Course	View details
Advanced General Relativity - Lecture 16	2013‑03‑14	Elements of General Relativity	Course	View details
A CDT Hamiltonian from Horava-Lifshitz gravity	2013‑03‑14	Quantum Gravity	Scientific Series	View details
The dynamics of asymptotically anti-de Sitter spacetimes	2013‑03‑14	Strong Gravity	Scientific Series	View details
The Higgs confronts 3 universes at the LHC	2013‑03‑13	Colloquium	Scientific Series	View details
Advanced General Relativity - Lecture 15	2013‑03‑12	Elements of General Relativity	Course	View details
Neorealism and the Internal Language of Topoi	2013‑03‑12	Quantum Foundations	Scientific Series	View details
Large N Chern-Simons-matter theories and three dimensional bosonization	2013‑03‑12	Quantum Fields and Strings	Scientific Series	View details

Supported by

Format results

The Effective Field Theory of Large Scale Structures

12/13 PSI - Explorations in Particle Theory Lecture 2

12/13 PSI - Explorations on Quantum Information Lecture 2

12/13 PSI - Explorations in Particle Theory Lecture 1

12/13 PSI - Explorations on Quantum Information Lecture 1

Advanced General Relativity - Lecture 16

A CDT Hamiltonian from Horava-Lifshitz gravity

The dynamics of asymptotically anti-de Sitter spacetimes

The Higgs confronts 3 universes at the LHC

Advanced General Relativity - Lecture 15

Neorealism and the Internal Language of Topoi

Large N Chern-Simons-matter theories and three dimensional bosonization

The Effective Field Theory of Large Scale Structures

12/13 PSI - Explorations in Particle Theory Lecture 2

12/13 PSI - Explorations on Quantum Information Lecture 2

12/13 PSI - Explorations in Particle Theory Lecture 1

12/13 PSI - Explorations on Quantum Information Lecture 1

Advanced General Relativity - Lecture 16

A CDT Hamiltonian from Horava-Lifshitz gravity

The dynamics of asymptotically anti-de Sitter spacetimes

The Higgs confronts 3 universes at the LHC

Advanced General Relativity - Lecture 15

Neorealism and the Internal Language of Topoi

Large N Chern-Simons-matter theories and three dimensional bosonization