Scientific Series

Displaying 3073 - 3084 of 5008

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
Sequential growth dynamics and quantum random walks

David Meyer University of California, San Diego
June 11, 2014

PIRSA:14060042
Mathematical Physics
Wild and tame scalar-tensor black holes

Valerio Faraoni Bishop's University
June 10, 2014

PIRSA:14060043
Astrophysics
Neutrino Wakes

Ue-Li Pen Canadian Institute for Theoretical Astrophysics (CITA)
June 06, 2014

PIRSA:14060041
Astrophysics
Quantum technologies as tools to deepen our understanding of quantum theory and relativity

Ivette Fuentes University of Southampton
June 05, 2014

PIRSA:14060006
Quantum Physics
How Much Information Can SUSY QM Conserve About SUSY QFT (Part-2)?

S. James Gates Jr. University of Maryland, College Park

June 04, 2014

PIRSA:14060005

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.
Sequential growth dynamics and quantum random walks

David Meyer University of California, San Diego
June 11, 2014

PIRSA:14060042
Mathematical Physics
Rideout and Sorkin proposed a classical dynamics for causal sets based upon a sequential growth model. Comparing it with models for sequential growth in other systems, and with the dual goals of generating manifold-like causal sets and finding a quantum dynamics for them, we propose some modifications to their model. The resulting, admittedly speculative, proposal is a type of quantum random walk. We explore its properties in some simple cases.
Wild and tame scalar-tensor black holes

Valerio Faraoni Bishop's University
June 10, 2014

PIRSA:14060043
Astrophysics
In scalar-tensor gravity, black holes do not obey the Jebsen-Birkhoff theorem. Non-isolated black holes can be highly dynamical and the teleological concept of event horizon is replaced by the apparent or trapping horizon. Dynamical solutions describing inhomogeneities embedded in cosmological "backgrounds" and the phenomenology of their apparent horizons, which often appear/vanish in pairs, will be described. Isolated black holes, in contrast, have no hair and are the same as in general relativity.
Neutrino Wakes

Ue-Li Pen Canadian Institute for Theoretical Astrophysics (CITA)
June 06, 2014

PIRSA:14060041
Astrophysics
We identify a new non-linear neutrino wake effect, due to the streaming motions of neutrinos relative to dark matter, analogous to the Tseliakhovich-Hirata effect. We compute the effect in moving background perturbation theory, compare to direct n-body simulations, and forecast its observability in current and future surveys. Depending on neutrino mass, this effect could be observable in upcoming surveys through a cross correlation dipole in lensing and galaxies. Unlike previous cosmological neutrino effects, this depends primarily on neutrino mass, making it complementary to measurements that depend on neutrino density.
Quantum technologies as tools to deepen our understanding of quantum theory and relativity

Ivette Fuentes University of Southampton
June 05, 2014

PIRSA:14060006
Quantum Physics
Quantum information and quantum metrology can be used to study gravitational effects such as gravitational waves and the universality of the equivalence principle. On one hand, the possibility of carrying out experiments to probe gravity using quantum systems opens an avenue to deepen our understanding of the overlap of these theories. On the other hand, incorporating relativity in quantum technologies promises the development of a new generation of relativistic quantum applications of relevance in Earth-based and space-based setups. In this talk, I will introduce a framework for the application of quantum information and quantum metrology techniques to relativistic quantum fields. I will show how, using this framework, we have been able to develop an accelerometer and a gravitational wave detector which exploit both quantum and relativistic effects. Moreover, our framework can be used to estimate with high precision spacetime parameters such as the Earth's Schwarzchild radius and the gravitational constant.
How Much Information Can SUSY QM Conserve About SUSY QFT (Part-2)?

S. James Gates Jr. University of Maryland, College Park

June 04, 2014

PIRSA:14060005

We provide additional evidence that supersymmetrical quantum mechanical systems can contain a remarkable amount of information about supersymmetrical field
theories in greater than one dimension.

Title	Speaker(s)	Date	Talk Type	Info link
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
Sequential growth dynamics and quantum random walks	David Meyer	2014-06-11	Scientific Series	View details
Wild and tame scalar-tensor black holes	Valerio Faraoni	2014-06-10	Scientific Series	View details
Neutrino Wakes	Ue-Li Pen	2014-06-06	Scientific Series	View details
Quantum technologies as tools to deepen our understanding of quantum theory and relativity	Ivette Fuentes	2014-06-05	Scientific Series	View details
How Much Information Can SUSY QM Conserve About SUSY QFT (Part-2)?	S. James Gates Jr.	2014-06-04	Scientific Series	View details

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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

Sequential growth dynamics and quantum random walks

Wild and tame scalar-tensor black holes

Neutrino Wakes

Quantum technologies as tools to deepen our understanding of quantum theory and relativity

How Much Information Can SUSY QM Conserve About SUSY QFT (Part-2)?

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

Sequential growth dynamics and quantum random walks

Wild and tame scalar-tensor black holes

Neutrino Wakes

Quantum technologies as tools to deepen our understanding of quantum theory and relativity

How Much Information Can SUSY QM Conserve About SUSY QFT (Part-2)?