Scientific Series

Displaying 3205 - 3216 of 5131

Neutrino Wakes

Ue-Li Pen University of Toronto
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
Gauge fields in de Sitter space: antipodal symmetry and holography

Yasha Neiman Okinawa Institute of Science and Technology Graduate University
June 03, 2014

PIRSA:14060039
High Energy Physics
Some Conceptual Problems in General Relativity and Cosmology

Jayant Narlikar IUCAA - The Inter-University Centre for Astronomy and Astrophysics
June 03, 2014

PIRSA:14060004
Astrophysics
Last gasp ‎of a black hole: why unitary evaporation must be non-monotonic

Matteo Smerlak Capital Fund Management S.A.
May 29, 2014

PIRSA:14050027
General Relativity & Quantum Cosmology
Phenomenology of charge order in underdoped cuprates

Andrea Allais Harvard University

May 27, 2014

PIRSA:14050147
A mechanism for vortex annihilation in two dimensional superfluid turbulence

Andrew Lucas University of Colorado Boulder
May 22, 2014

PIRSA:14050139
General Relativity & Quantum Cosmology
Are the recent IceCube events hinting at O(100) TeV decaying dark matter?

Atri Bhattacharya University of Liège
May 22, 2014

PIRSA:14050118
High Energy Physics
Equality

Tobias Fritz Universität Innsbruck

May 21, 2014

PIRSA:14050063
Local quanta, unitary inequivalence, and vacuum entanglement

Hans Westman
May 20, 2014

PIRSA:14050117
Quantum Physics
Designing exotic circuitry with non-Abelian anyons
May 20, 2014

PIRSA:14050029
Condensed Matter

Neutrino Wakes

Ue-Li Pen University of Toronto
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.
Gauge fields in de Sitter space: antipodal symmetry and holography

Yasha Neiman Okinawa Institute of Science and Technology Graduate University
June 03, 2014

PIRSA:14060039
High Energy Physics
There is a proposed dS/CFT duality in 3+1 dimensions, with higher-spin gravity in the bulk subject to Bunch-Davies boundary conditions. I consider replacing these with antipodally symmetric conditions, which allow for real values of the bulk fields. I present spanning sets of solutions in global dS_4 for free gauge fields of all spins (including photons and gravitons), and use them to establish relations between antipodal symmetry and asymptotic behavior. Some of these relations can be extended to interacting theories, including ordinary and higher-spin gravity. I discuss the implications for antipodally symmetric dS/CFT.
Some Conceptual Problems in General Relativity and Cosmology

Jayant Narlikar IUCAA - The Inter-University Centre for Astronomy and Astrophysics
June 03, 2014

PIRSA:14060004
Astrophysics
This talk will try to highlight some basic problems connected with conclusions uncritically drawn from well known works. These include: 1. The Schwarzschild solution 2. The formation of black holes by gravitational collapse 3. The no hair theorem 4. The principle of equivalence in the very early universe.
Last gasp ‎of a black hole: why unitary evaporation must be non-monotonic

Matteo Smerlak Capital Fund Management S.A.
May 29, 2014

PIRSA:14050027
General Relativity & Quantum Cosmology
I will describe the relationship between radiated energy and entanglement entropy of massless fields at future null infinity (the "Page curve") in two-dimensional models of black hole evaporation. ‎I will use this connection to derive a general feature of any unitary-preserving evaporation scenario: the Bondi mass of the hole must be non-monotonic. Time permitting, I will comment on time scales in such scenarios.
Phenomenology of charge order in underdoped cuprates

Andrea Allais Harvard University

May 27, 2014

PIRSA:14050147

In the past few years substantial evidence has been collected that points to coexistence of charge correlations with long range superconductivity in underdoped cuprate superconductors. In this talk I will review some of this evidence, then show that a charge density wave with precisely the same signatures is a natural instability of an antiferromagnetic metal, and finally derive some phenomenological consequences, with special focus on quantum oscillation experiments.
A mechanism for vortex annihilation in two dimensional superfluid turbulence

Andrew Lucas University of Colorado Boulder
May 22, 2014

PIRSA:14050139
General Relativity & Quantum Cosmology
Recent numerical simulations [1] have suggested that two dimensional superfluid turbulence is characterized by a direct cascade of energy to small length scales, in contrast to the inverse cascade of normal fluids, where energy is transported to large length scales. This direct cascade is characterized by many vortex-antivortex annihilation events. Recent experimental work [2] on Bose-Einstein condensates appears to demonstrate qualitatively similar physics. I will discuss recent work in progress towards identifying the physical mechanism underlying this direct cascade, using techniques of effective field theory.
Are the recent IceCube events hinting at O(100) TeV decaying dark matter?

Atri Bhattacharya University of Liège
May 22, 2014

PIRSA:14050118
High Energy Physics
The IceCube detector has recently reported the observation of 28 events at previously unexplored energies. While the statistics of the observed events are still low, these events hint at the existence of a neutrino flux over and above the atmospheric neutrino background. We investigate the possibility that a significant component of the additional neutrino flux originates due to the decay of a very heavy dark matter (VHDM) particle via several possible channels into standard model particles. We show that a combination of a power law astrophysical neutrino spectrum and the neutrino flux from the decay of a DM species of mass in the range 150-400 TeV improves the fit to the observed neutrino events than that obtained from a best-fit astrophysical flux alone. Assuming the existence of an astrophysical background described by the IC best-fit, we also show that, for the decay of even heavier DM particles ($m_{\text{DM}} \sim 1$ PeV), the same observations impose significant constraints on the decay lifetimes. Allowing the astrophysical flux normalization to vary leads to modifications of these limits; however, there is still a range of dark matter mass and lifetime that is excluded by the IC results.
Equality

Tobias Fritz Universität Innsbruck

May 21, 2014

PIRSA:14050063

Equality of two mathematical objects is a seemingly simple and well-understood concept. In this talk, I will do three things to explain why this is a misconception: I will survey different notions of equality, explain how revising the notion of equality has led to an emerging alternative foundation of mathematics called "homotopy type theory", and try to convince you that thinking about equality is relevant to your research in quantum field theory, quantum gravity or quantum foundations.
Local quanta, unitary inequivalence, and vacuum entanglement

Hans Westman
May 20, 2014

PIRSA:14050117
Quantum Physics
In this work we develop a formalism for describing localised quanta for a real-valued Klein-Gordon field in a one-dimensional box [0, R]. We quantise the field using non-stationary local modes which, at some arbitrarily chosen initial time, are completely localised within the left or the right side of the box. In this concrete set-up we directly face the problems inherent to a notion of local field excitations, usually thought of as elementary particles. Specifically, by computing the Bogoliubov coefficients relating local and standard (global) quantizations, we show that the local quantisation yields a Fock space F^L which is unitarily inequivalent to the standard one F^G. In spite of this, we find that the local creators and annihilators remain well defined in the global Fock space F^G, and so do the local number operators associated to the left and right partitions of the box. We end up with a useful mathematical toolbox to analyse and characterise local features of quantum states in F^G . Specifically, an analysis of the global vacuum state |0_G> ∈ F^G in terms of local number operators shows, as expected, the existence of entanglement between the left and right regions of the box. The local vacuum |0_L> ∈ F^L , on the contrary, has a very different character. It is neither cyclic nor separating and displays no entanglement. Further analysis shows that the global vacuum also exhibits a distribution of local excitations reminiscent, in some respects, of a thermal bath. We discuss how the mathematical tools developed herein may open new ways for the analysis of fundamental problems in local quantum field theory.
Designing exotic circuitry with non-Abelian anyons
May 20, 2014

PIRSA:14050029
Condensed Matter
Non-Abelian anyons are widely sought for the exotic fundamental physics they harbor as well as for their possible applications for quantum information processing. Currently, there are numerous blueprints for stabilizing the simplest type of non-Abelian anyon, a Majorana zero energy mode bound to a vortex or a domain wall. One such candidate system, a so-called "Majorana wire" can be made by judiciously interfacing readily available materials; the experimental evidence for the viability of this approach is presently emerging.
Following this idea, we introduce a device fabricated from conventional fractional quantum Hall states, s-wave superconductors and insulators with strong spin-orbit coupling. Similarly to a Majorana wire, the ends of our “quantum wire” would bind "parafermions", exotic non-Abelian anyons which can be viewed as fractionalised Majorana zero modes.
I will discuss their properties and describe how such parafermions can be used to construct new and potentially useful circuit elements which include current and voltage mirrors, transistors for fractional charge currents and "flux capacitors".

Title	Speaker(s)	Date	Talk Type	Info link
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
Gauge fields in de Sitter space: antipodal symmetry and holography	Yasha Neiman	2014-06-03	Scientific Series	View details
Some Conceptual Problems in General Relativity and Cosmology	Jayant Narlikar	2014-06-03	Scientific Series	View details
Last gasp ‎of a black hole: why unitary evaporation must be non-monotonic	Matteo Smerlak	2014-05-29	Scientific Series	View details
Phenomenology of charge order in underdoped cuprates	Andrea Allais	2014-05-27	Scientific Series	View details
A mechanism for vortex annihilation in two dimensional superfluid turbulence	Andrew Lucas	2014-05-22	Scientific Series	View details
Are the recent IceCube events hinting at O(100) TeV decaying dark matter?	Atri Bhattacharya	2014-05-22	Scientific Series	View details
Equality	Tobias Fritz	2014-05-21	Scientific Series	View details
Local quanta, unitary inequivalence, and vacuum entanglement	Hans Westman	2014-05-20	Scientific Series	View details
Designing exotic circuitry with non-Abelian anyons		2014-05-20	Scientific Series	View details

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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)?

Gauge fields in de Sitter space: antipodal symmetry and holography

Some Conceptual Problems in General Relativity and Cosmology

Last gasp ‎of a black hole: why unitary evaporation must be non-monotonic

Phenomenology of charge order in underdoped cuprates

A mechanism for vortex annihilation in two dimensional superfluid turbulence

Are the recent IceCube events hinting at O(100) TeV decaying dark matter?

Equality

Local quanta, unitary inequivalence, and vacuum entanglement

Designing exotic circuitry with non-Abelian anyons

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)?

Gauge fields in de Sitter space: antipodal symmetry and holography

Some Conceptual Problems in General Relativity and Cosmology

Last gasp ‎of a black hole: why unitary evaporation must be non-monotonic

Phenomenology of charge order in underdoped cuprates

A mechanism for vortex annihilation in two dimensional superfluid turbulence

Are the recent IceCube events hinting at O(100) TeV decaying dark matter?

Equality

Local quanta, unitary inequivalence, and vacuum entanglement

Designing exotic circuitry with non-Abelian anyons