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Search results in High Energy Physics from PIRSA

1789 - 1800 of 2995 Results

From Effective Strings to the Simplest theory of Quantum Gravity
October 23, 2012

PIRSA:12100040
High Energy Physics
New Results in Jet Substructure
October 23, 2012

PIRSA:12100128
High Energy Physics
An informal discussion about topological gauge theory

Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics
October 23, 2012

PIRSA:12100129
High Energy Physics
Quantum Field Theory - Lecture 11B

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 23, 2012

PIRSA:12100072
High Energy Physics
Quantum Field Theory - Lecture 11A

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 23, 2012

PIRSA:12100018
High Energy Physics
Photons and Quantum Gravity in Astrophysics
- Robert Nemiroff Michigan Technological University
- Giovanni Amelino-Camelia Sapienza Università di Roma - Dipartimento di Fisica
- Niayesh Afshordi University of Waterloo
- Joao Magueijo Imperial College London
- Alfio Bonanno National Institute for Astrophysics (INAF)
- Robert Brandenberger McGill University - Department of Physics
October 22, 2012

PIRSA:12100085
General Relativity & Quantum Cosmology

High Energy Physics
Quantum Field Theory - Lecture 10B

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 22, 2012

PIRSA:12100071
High Energy Physics
Quantum Field Theory - Lecture 10A

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 22, 2012

PIRSA:12100017
High Energy Physics
Quantum Field Theory - Lecture 9B

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 19, 2012

PIRSA:12100070
High Energy Physics
Quantum Field Theory - Lecture 9A

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 19, 2012

PIRSA:12100014
High Energy Physics
Towards an Asymptotically AdS Description of Heavy Ion Collisions

Hans Bantilan Princeton University
October 18, 2012

PIRSA:12100076
High Energy Physics
Quantum Field Theory - Lecture 8B

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 18, 2012

PIRSA:12100069
High Energy Physics

From Effective Strings to the Simplest theory of Quantum Gravity
October 23, 2012

PIRSA:12100040
High Energy Physics
String-like objects arise in many quantum field theories. Well known examples include flux tubes in QCD and cosmic strings. To a first approximation, their dynamics is governed by the Nambu-Goto action, but for QCD flux tubes numerical calculations of the energy levels of these objects have become so accurate that a systematic understanding of corrections to this simple description is desirable. In the first part of my talk, I discuss an effective field theory describing long relativistic strings. The construction parallels that of the chiral Lagrangian in that it is based on the pattern of symmetry breaking. To compare with previous works, I will present the results of the calculation of the S-matrix describing the scattering of excitations on the string worldsheet. In the second part of my talk, I will discuss critical strings from the same point of view and show that the worldsheet S-matrix in this case is non-trivial but can be calculated exactly. I will show that it encodes the familiar square-root formula for the energy levels of the string, the Hagedorn behavior of strings, and argue that the theory on the string worldsheet behaves like a 1+1 dimensional theory of quantum gravity rather than a field theory. If time permits, I will return to the task of computing the energy levels of flux-tubes using lessons learned from the second part of my talk.
New Results in Jet Substructure
October 23, 2012

PIRSA:12100128
High Energy Physics
We present new results on the performance of jet substructure techniques and their use in distinguishing the signatures of new boosted massive particles from the QCD background. Advanced approaches to jet reconstruction using jet grooming algorithms such as filtering, trimming, and pruning are compared. Measurements of the jet invariant mass for each jet algorithm are compared both at the particle level to multiple Monte Carlo event generators and at the detector level for several configurations of the jet grooming algorithms. The performance of these strategies and improvements in search sensitivity for new boosted hadronic particles are compared. Recent results using these techniques for both boosted RPV gluinos and top quark pairs from new particles are presented. The result is a comprehensive foundation for the use of substructure algorithms in the search for new physics at the LHC
An informal discussion about topological gauge theory

Xiao-Gang Wen Massachusetts Institute of Technology (MIT) - Department of Physics
October 23, 2012

PIRSA:12100129
High Energy Physics
Reference:
Topological gauge theories and group cohomology
Robbert Dijkgraaf and Edward Witten
http://projecteuclid.org/DPubS?service=UI&version=1.0&verb=Display&handle=euclid.cmp/1104180750

Braiding statistics approach to symmetry-protected topological phases
Michael Levin, Zheng-Cheng Gu
http://arxiv.org/abs/1202.3120
Quantum Field Theory - Lecture 11B

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 23, 2012

PIRSA:12100072
High Energy Physics
Quantum Field Theory - Lecture 11A

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 23, 2012

PIRSA:12100018
High Energy Physics
Photons and Quantum Gravity in Astrophysics
- Robert Nemiroff Michigan Technological University
- Giovanni Amelino-Camelia Sapienza Università di Roma - Dipartimento di Fisica
- Niayesh Afshordi University of Waterloo
- Joao Magueijo Imperial College London
- Alfio Bonanno National Institute for Astrophysics (INAF)
- Robert Brandenberger McGill University - Department of Physics
October 22, 2012

PIRSA:12100085
General Relativity & Quantum Cosmology

High Energy Physics
Asymptotically safe inflation and CMB polarization
The presence of complex critical exponents in the scaling behavior of the Newton constant and Cosmological constant has dramatic consequences at the inflation scale. In particular an infinite number of unstable de-Sitter vacua emerges from an effective quantum gravitational action. In this framework, the possibility of detecting specific signaturesof a non-gaussian fixed point of the gravitational interactions in the CMB polarization spectrum will then be discussed.

________________________

Cosmological windows such as CMB polarization and 21cm redshift surveys to probe Planck-scale physics

________________________

Quantum gravity and a chiral signature in gravity waves
I show how quantum gravity could lead to a chiral signature in the graviational wave background, proportional to the imaginary part of the Immirzi parameter. This would leave a distinctive imprint in the polarization of the cosmic microwave background. I will discuss how this isue is closely related to that of identifying the ground of base state for quantum gravity.

_______________________

A Possible Bound on Spectral Dispersion from Fermi-Detected Gamma Ray Burst 090510A
Three photons spanning about 30 GeV arrived within about one millisecond from the Fermi-detected GRB 090510A at a redshift of about 0.9. Although conceivably a > 3Ïƒ statistical fluctuation when taken at face value this photon bunch -- quite possibly a classic GRB pulse -- leads to a relatively tight bound on the ability of our universe to disperse high energy photons. Specifically given a generic dispersion relation where the time delay is proportional to the photon energy to the first power the limit on the dispersion strength is k1 < 1.61Ã—10-5 sec Gpc-1 GeV-1. In the context of some theories of quantum gravity this conservative bound translates into an minimum energy scale greater than 525 m_Planck suggesting that spacetime is smooth at energies perhaps three orders of magnitude over the Planck mass.
Quantum Field Theory - Lecture 10B

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 22, 2012

PIRSA:12100071
High Energy Physics
Quantum Field Theory - Lecture 10A

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 22, 2012

PIRSA:12100017
High Energy Physics
Quantum Field Theory - Lecture 9B

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 19, 2012

PIRSA:12100070
High Energy Physics
Quantum Field Theory - Lecture 9A

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 19, 2012

PIRSA:12100014
High Energy Physics
Towards an Asymptotically AdS Description of Heavy Ion Collisions

Hans Bantilan Princeton University
October 18, 2012

PIRSA:12100076
High Energy Physics
I will discuss recent work in simulating asymptotically anti-de Sitter spacetimes, and its relation to heavy ion collider physics. For this purpose, I intend to focus on a class of oblately deformed black hole spacetime solutions. For each of these solutions, I will map the gravitational metric in the spacetime bulk to a stress tensor one-point function of the conformal field theory defined on the spacetime boundary. During the ring-down process, wherein the deformed black hole settles down to the AdS analog of the Schwarzschild solution, I will exhibit evidence that the dual CFT stress tensor on the boundary is that of an N=4 SYM fluid, even for black holes of significant deformation well outside the perturbative regime. We will conformally map the boundary fluid onto a real-world fluid in Minkowski space, and discover a temperature profile which can be thought of as approximating that of a head-on heavy ion collision at its moment of impact. I will close with a description of recent parallel explorations.
Quantum Field Theory - Lecture 8B

Konstantin Zarembo Nordic Institute for Theoretical Physics
October 18, 2012

PIRSA:12100069
High Energy Physics

Title	Date	Collection	Type	Info
From Effective Strings to the Simplest theory of Quantum Gravity	2012‑10‑23	Quantum Fields and Strings	Scientific Series	View details
New Results in Jet Substructure	2012‑10‑23	Particle Physics	Scientific Series	View details
An informal discussion about topological gauge theory	2012‑10‑23	Quantum Matter	Scientific Series	View details
Quantum Field Theory - Lecture 11B	2012‑10‑23	12/13 PSI - Quantum Field Theory 1	Course	View details
Quantum Field Theory - Lecture 11A	2012‑10‑23	12/13 PSI - Quantum Field Theory 1	Course	View details
Photons and Quantum Gravity in Astrophysics	2012‑10‑22	Experimental Search for Quantum Gravity 2012	Conference	View details
Quantum Field Theory - Lecture 10B	2012‑10‑22	12/13 PSI - Quantum Field Theory 1	Course	View details
Quantum Field Theory - Lecture 10A	2012‑10‑22	12/13 PSI - Quantum Field Theory 1	Course	View details
Quantum Field Theory - Lecture 9B	2012‑10‑19	12/13 PSI - Quantum Field Theory 1	Course	View details
Quantum Field Theory - Lecture 9A	2012‑10‑19	12/13 PSI - Quantum Field Theory 1	Course	View details
Towards an Asymptotically AdS Description of Heavy Ion Collisions	2012‑10‑18	Strong Gravity	Scientific Series	View details
Quantum Field Theory - Lecture 8B	2012‑10‑18	12/13 PSI - Quantum Field Theory 1	Course	View details

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Format results

From Effective Strings to the Simplest theory of Quantum Gravity

New Results in Jet Substructure

An informal discussion about topological gauge theory

Quantum Field Theory - Lecture 11B

Quantum Field Theory - Lecture 11A

Photons and Quantum Gravity in Astrophysics

Quantum Field Theory - Lecture 10B

Quantum Field Theory - Lecture 10A

Quantum Field Theory - Lecture 9B

Quantum Field Theory - Lecture 9A

Towards an Asymptotically AdS Description of Heavy Ion Collisions

Quantum Field Theory - Lecture 8B

From Effective Strings to the Simplest theory of Quantum Gravity

New Results in Jet Substructure

An informal discussion about topological gauge theory

Quantum Field Theory - Lecture 11B

Quantum Field Theory - Lecture 11A

Photons and Quantum Gravity in Astrophysics

Quantum Field Theory - Lecture 10B

Quantum Field Theory - Lecture 10A

Quantum Field Theory - Lecture 9B

Quantum Field Theory - Lecture 9A

Towards an Asymptotically AdS Description of Heavy Ion Collisions

Quantum Field Theory - Lecture 8B