Scientific Series

Displaying 3145 - 3156 of 5085

Exploring N=1 theories of class S through Higgsing, dualizing and twisting

Jaewon Song University of California, San Diego
July 15, 2014

PIRSA:14070024
High Energy Physics
Improving Mass Measurements Using Many-Body Phase Space

Can Kilic The University of Texas at Austin
July 15, 2014

PIRSA:14070023
High Energy Physics
Cosmological Coincidence Problem
July 15, 2014

PIRSA:14070030
Astrophysics
Strong majorization entropic uncentainty relations

Karol Zyczkowski Jagiellonian University
July 14, 2014

PIRSA:14070017
Quantum Physics
TBA
July 08, 2014

PIRSA:14070018
Condensed Matter
Numerical investigations of singularities in general relativity

David Garfinkle Oakland University
June 26, 2014

PIRSA:14060052
Astrophysics
On Quantum Tunnelling

Neil Turok University of Edinburgh
June 25, 2014

PIRSA:14060051
Astrophysics
Gravity, an unexpected journey: from thermodynamics to emergent gravity, Lorentz breaking and back...

Stefano Liberati SISSA International School for Advanced Studies
June 19, 2014

PIRSA:14060002
General Relativity & Quantum Cosmology
Analogue Models of Gravity: The ubiquitous space-time

Stefano Liberati SISSA International School for Advanced Studies
June 18, 2014

PIRSA:14060000
General Relativity & Quantum Cosmology
The Exact Renormalization Group and Higher Spin Holography.

Rob Leigh University of Illinois Urbana-Champaign
June 17, 2014

PIRSA:14060047
High Energy Physics
What Can We Learn from Precision Higgs

Maxim Perelstein Cornell University
June 13, 2014

PIRSA:14060003
High Energy Physics
Inflation, Variable Speed of Light and BICEP2

John Moffat Perimeter Institute for Theoretical Physics
June 12, 2014

PIRSA:14060044
Astrophysics

Exploring N=1 theories of class S through Higgsing, dualizing and twisting

Jaewon Song University of California, San Diego
July 15, 2014

PIRSA:14070024
High Energy Physics
We study a class of 4d N=1 SCFTs obtained from partial compactifications of 6d N=(2, 0) theory on a Riemann surface with punctures. We identify theories corresponding to curves with general type of punctures through nilpotent Higgsing and Seiberg dualities. The `quiver tails' of N=1 class S theories turn out to differ significantly from N=2 counterpart and have interesting properties. Various dual descriptions for such a theory can be found by using colored pair-of-pants decompositions. Especially, we find N=1 analog of Argyres-Seiberg duality for the SQCD with various gauge groups. We compute anomaly coefficients and superconformal indices to verify our proposal.
Improving Mass Measurements Using Many-Body Phase Space

Can Kilic The University of Texas at Austin
July 15, 2014

PIRSA:14070023
High Energy Physics
After the 7 and 8 TeV LHC runs, we have no conclusive evidence of physics beyond the Standard Model, leading us to suspect that even if new physics is discovered during run II, the number of signal events may be limited, making it crucial to optimize measurements for the case of low statistics. I will argue that phase space correlations between subsequent on-shell decays in a cascade contain additional information compared to commonly used kinematic variables, and this can be used to significantly improve the precision and accuracy of mass measurements. The improvement is connected to the properties of the volume element of many-body phase space, and is particularly relevant to the case of low signal statistics.
Cosmological Coincidence Problem
July 15, 2014

PIRSA:14070030
Astrophysics
I will try to explain how cosmological coincidence of the two values, the matter energy density and the dark energy density, at the present epoch based on a single scalar field model whith a quartic potential, non-mimimally interacting with gravity. Dark energy in this model originates from the potential energy of the scalar field, which is sourced by the appearance of non-relativistic matter at the time z~ 10^10. No fine tuning of parameter are neccessary.
Strong majorization entropic uncentainty relations

Karol Zyczkowski Jagiellonian University
July 14, 2014

PIRSA:14070017
Quantum Physics
We analyze entropic uncertainty relations in a finite dimensional Hilbert space and derive several strong bounds for the sum of two entropies obtained in projective measurements with respect to any two orthogonal bases. We improve the recent bounds by Coles and Piani, which are known to be stronger than the well known result of Maassen and Uffink. Furthermore, we find a novel bound based on majorization techniques, which also happens to be stronger than the recent results involving largest singular values of submatrices of the unitary matrix connecting both bases. The first set of new bounds give better results for unitary matrices close to the Fourier matrix, while the second one provides a significant improvement in the opposite sectors. Some results derived admit generalization to arbitrary mixed states, so that corresponding bounds are increased by the von Neumann entropy of the measured state. The majorization approach is finally extended to the case of several measurements.
TBA
July 08, 2014

PIRSA:14070018
Condensed Matter
Numerical investigations of singularities in general relativity

David Garfinkle Oakland University
June 26, 2014

PIRSA:14060052
Astrophysics
The singularity theorems of general relativity tell us that spacetime singularities form in gravitational collapse, but tell us very little about the precise nature of these singularities. More information can be found using analytic approximations and numerical simulations. It is conjectured that inside black holes are two types of singularities: one that is spacelike, local, and oscillatory, and the other that is null and weak. This talk will review what numerical simulations of singularities have been done and the extent to which the above conjecture has been verified by the simulations.
On Quantum Tunnelling

Neil Turok University of Edinburgh
June 25, 2014

PIRSA:14060051
Astrophysics
One of the most basic but intriguing properties of quantum systems is their ability to `tunnel' between configurations which are classically disconnected. That is, processes which are classically impossible, are quantum allowed. In this talk I will outline a new, first-principles approach combining the semiclassical approximation with the concepts of post-selection and weak measurement. Its main virtue is to provide a real-time description within which sharp answers can be given to questions such as 'how long did the tunneling take' and 'where was the particle while it was tunneling?' Potential applications span a vast range, from laboratory tests to understanding black hole evaporation, the stability of the electroweak Higgs vacuum and the future of our universe, and the validity (or otherwise) of the "inflationary multiverse" scenario.
Gravity, an unexpected journey: from thermodynamics to emergent gravity, Lorentz breaking and back...

Stefano Liberati SISSA International School for Advanced Studies
June 19, 2014

PIRSA:14060002
General Relativity & Quantum Cosmology
Thermodynamical aspects of gravity have been a tantalising puzzle for more than forty years now and are still at the center of much activity in semiclassical and quantum gravity. We shall explore the possibility that they might hint toward an emergent nature of gravity exploring the possible implications of such hypothesis. Among these we shall focus on the possibility that Lorentz invariance might be only a low energy/emergent feature by discussing viable theoretical frameworks, present constraints and open issues which make this path problematic. In the end we shall focus on black hole thermodynamics in Lorentz breaking gravity by presenting some recent results that seems to hint towards a surprising resilience of thermodynamics aspect of gravity even in these scenarios.
Analogue Models of Gravity: The ubiquitous space-time

Stefano Liberati SISSA International School for Advanced Studies
June 18, 2014

PIRSA:14060000
General Relativity & Quantum Cosmology
Analogies have played a very important role in physics and mathematics, as they provide new ways of looking at problems that permit cross-fertilization of ideas among different branches of science. An analogue gravity model is a generic dynamical system (typically but not always based on condensed matter physics) where the propagation of excitations/perturbations can be described via hyperbolic equations of motion possibly characterized be one single metric element for all the perturbations. We shall review the historical development of this field, some of the systems proposed, and discuss several applications of this fruitful analogy mainly in the context of black hole physics and cosmology. While typical applications are in the realm of classical and quantum field theory on curved spacetime, I shall in the end also discuss recent developments which may provide insights about the possible nature of gravitational dynamics in emergent gravity scenarios.
The Exact Renormalization Group and Higher Spin Holography.

Rob Leigh University of Illinois Urbana-Champaign
June 17, 2014

PIRSA:14060047
High Energy Physics
What Can We Learn from Precision Higgs

Maxim Perelstein Cornell University
June 13, 2014

PIRSA:14060003
High Energy Physics
In the coming years, LHC experiments will measure Higgs properties, such as its couplings, with increasing precision. Electron-positron Higgs factories, such as the ILC or TLEP, would be able to achieve even better precision. In this talk, I will discuss some of the physics questions that can be addressed by a precision Higgs coupling measurement program. First, the issue of naturalness of the electroweak scale can be addressed in a robust, model-independent manner. Second, the possibility of a first-order electroweak phase transition can be definitively probed, testing one of the necessary conditions of electroweak baryogenesis scenario.
Inflation, Variable Speed of Light and BICEP2

John Moffat Perimeter Institute for Theoretical Physics
June 12, 2014

PIRSA:14060044
Astrophysics
A variable speed of light (VSL) cosmology is developed with a spontaneous breaking of Lorentz invariance in the early universe. A non-minimal electromagnetic coupling to curvature and the resulting quantum electrodynamic vacuum polarization dispersive medium can produce c >> c0 in the early universe, where c0 is the measured speed of light today. Higher derivative curvature contributions to the effective gravitational action and quantum gravity vacuum polarization can produce a dispersive medium and a large increase in the speed of gravitational waves cg >> cg0 in the early universe, where cg0 is the speed of gravitational waves today. The initial value problems of cosmology are solved: the horizon and flatness problems. The model predicts primordial scalar and tensor fluctuation spectral indices ns=0.96 and nt=- 0.04, respectively. The BICEP2 observation of r=0.2 yields r/nt=-5 which is close to the single-field inflationary consistency condition r/nt=-8.

Title	Speaker(s)	Date	Talk Type	Info link
Exploring N=1 theories of class S through Higgsing, dualizing and twisting	Jaewon Song	2014-07-15	Scientific Series	View details
Improving Mass Measurements Using Many-Body Phase Space	Can Kilic	2014-07-15	Scientific Series	View details
Cosmological Coincidence Problem		2014-07-15	Scientific Series	View details
Strong majorization entropic uncentainty relations	Karol Zyczkowski	2014-07-14	Scientific Series	View details
TBA		2014-07-08	Scientific Series	View details
Numerical investigations of singularities in general relativity	David Garfinkle	2014-06-26	Scientific Series	View details
On Quantum Tunnelling	Neil Turok	2014-06-25	Scientific Series	View details
Gravity, an unexpected journey: from thermodynamics to emergent gravity, Lorentz breaking and back...	Stefano Liberati	2014-06-19	Scientific Series	View details
Analogue Models of Gravity: The ubiquitous space-time	Stefano Liberati	2014-06-18	Scientific Series	View details
The Exact Renormalization Group and Higher Spin Holography.	Rob Leigh	2014-06-17	Scientific Series	View details
What Can We Learn from Precision Higgs	Maxim Perelstein	2014-06-13	Scientific Series	View details
Inflation, Variable Speed of Light and BICEP2	John Moffat	2014-06-12	Scientific Series	View details

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Exploring N=1 theories of class S through Higgsing, dualizing and twisting

Improving Mass Measurements Using Many-Body Phase Space

Cosmological Coincidence Problem

Strong majorization entropic uncentainty relations

TBA

Numerical investigations of singularities in general relativity

On Quantum Tunnelling

Gravity, an unexpected journey: from thermodynamics to emergent gravity, Lorentz breaking and back...

Analogue Models of Gravity: The ubiquitous space-time

The Exact Renormalization Group and Higher Spin Holography.

What Can We Learn from Precision Higgs

Inflation, Variable Speed of Light and BICEP2

Exploring N=1 theories of class S through Higgsing, dualizing and twisting

Improving Mass Measurements Using Many-Body Phase Space

Cosmological Coincidence Problem

Strong majorization entropic uncentainty relations

TBA

Numerical investigations of singularities in general relativity

On Quantum Tunnelling

Gravity, an unexpected journey: from thermodynamics to emergent gravity, Lorentz breaking and back...

Analogue Models of Gravity: The ubiquitous space-time

The Exact Renormalization Group and Higher Spin Holography.

What Can We Learn from Precision Higgs

Inflation, Variable Speed of Light and BICEP2