Talks

12505 - 12516 of 16353 Results

Quantum Tagging: Authenticating Location via Quantum Information and Relativistic Signalling Constraints

Adrian Kent
University of Cambridge

September 01, 2010

PIRSA:10090072
Introduction to Complex Analysis/Computer Skills - Lecture 3B

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

September 01, 2010

PIRSA:10090080
Introduction to Complex Analysis/Computer Skills - Lecture 3A

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

September 01, 2010

PIRSA:10090073
An Invitation into Eventum Mechanics of Quantum Information

Viacheslav Belavkin
University of Nottingham

August 31, 2010

PIRSA:10080038

Quantum Foundations
Introduction to Complex Analysis/Computer Skills - Lecture 2B

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

August 31, 2010

PIRSA:10080043
Introduction to Complex Analysis/Computer Skills - Lecture 2A

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

August 31, 2010

PIRSA:10080041
Introduction to Complex Analysis/Computer Skills - Lecture 1B

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

August 30, 2010

PIRSA:10080042
Introduction to Complex Analysis/Computer Skills - Lecture 1A

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

August 30, 2010

PIRSA:10080040
Space-time, Quantum Mechanics and Scattering Amplitudes

Freddy Cachazo
Perimeter Institute for Theoretical Physics

Nima Arkani-Hamed
Institute for Advanced Study (IAS)

August 27, 2010

PIRSA:10080022
Probability of slow roll inflation

Jason Hofgartner
Southwest Research Institute

August 27, 2010

PIRSA:10080039
PSI 2010 - Theoretical Physics - Lecture 5B

Nima Arkani-Hamed
Institute for Advanced Study (IAS)

August 27, 2010

PIRSA:10080037
Space-time, Quantum Mechanics and Scattering Amplitudes - 5A

Freddy Cachazo
Perimeter Institute for Theoretical Physics

Nima Arkani-Hamed
Institute for Advanced Study (IAS)

August 27, 2010

PIRSA:10080017

Quantum Tagging: Authenticating Location via Quantum Information and Relativistic Signalling Constraints

Adrian Kent
University of Cambridge

September 01, 2010

PIRSA:10090072

In this talk I review some joint work (arXiv:1008.2147) with Bill Munro and Tim Spiller on the task we call "quantum tagging", that is, authenticating the classical location of a classical tagging device by sending and receiving quantum signals from suitably located distant sites, in an environment controlled by an adversary whose quantum information processing and transmitting power is unbounded. Simple security models for this task will be presented. It will be shown that (among other protocols) recent protocols claimed to be unconditionally secure by Malaney and by Chandran et al. can in fact be broken by an adversary with pre-distributed entanglement using teleportation-based attacks. I also describe some protocols which cannot be broken by these specific attacks, but do not prove they are unconditionally secure. From a more foundational perspective, this work can be thought of (i) as an attempt to understand how and when we can know that something is somewhere, and (ii) an introduction to an interesting wider class of (im)possibility questions in relativistic quantum theory. If time permits, I will also touch on these topics.
Introduction to Complex Analysis/Computer Skills - Lecture 3B

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

September 01, 2010

PIRSA:10090080
Introduction to Complex Analysis/Computer Skills - Lecture 3A

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

September 01, 2010

PIRSA:10090073
An Invitation into Eventum Mechanics of Quantum Information

Viacheslav Belavkin
University of Nottingham

August 31, 2010

PIRSA:10080038

Quantum Foundations

Quantum states are not observables like in any wave mechanics but co-observables describing the reality as a possible knowledge about the statistics of all quantum events, like quantum jumps, quantum decays, quantum diffusions, quantum trajectories, etc. However, as we show, the probabilistic interpretation of the traditional quantum mechanics is inconsistent with the probbilistic causality and leads to the infamous quantum measurement problem. Moreover, we prove that all attempts to solve this problem as suggested by Bohr are doomed in the traditional framework of the reversible interactions. We explore the only possibility left to resolve the quantum causality problem while keeping the reversibility of Schroedinger mechanics. This is to break the time symmetry of the Heisenberg mechanics using the nonequivalence of the Schroedinger and Heisenberg quantum mechanics on nonsimple operator algebras in infinite dimensional Hilbert spaces. This is the main idea of Eventum Mechanics, which enhances the quantum world of the future by classical events of the past and constructs the reversible Schroedinger evolutions compatible with observable quantm trajectories by irreversible quantum to classicl interfaces in terms of the reversible unitary scatterings. It puts the idea of hidden variables upside down by declaring that what is visible (in the past by now) is not quantum but classical and what is visible (by now in the future) is quantum but not classical. More on the philosophy of Eventum Mechanics can be found in [1]. We demonstrate these ideas on the toy model of the nontrivial quantum - classical bit interface. The application of these ideas in the continuous time leads to derivation of the quantum stochastic master equations reviewed in [1] and of my research pages [3]. V. P. Belavkin: Quantum Causality, Stochastics, Trajectories and Information. Reports on Progress in Physics 65 (3): 353-420 (2002). quant-ph/0208087, PDF. http://www.maths.nott.ac.uk/personal/vpb/vpb_research.html http://www.maths.nott.ac.uk/personal/vpb/research/cau_idy.html
Introduction to Complex Analysis/Computer Skills - Lecture 2B

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

August 31, 2010

PIRSA:10080043
Introduction to Complex Analysis/Computer Skills - Lecture 2A

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

August 31, 2010

PIRSA:10080041
Introduction to Complex Analysis/Computer Skills - Lecture 1B

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

August 30, 2010

PIRSA:10080042
Introduction to Complex Analysis/Computer Skills - Lecture 1A

Pedro Vieira
Perimeter Institute for Theoretical Physics

Denis Dalidovich

Callum Durnford

Tibra Ali
Perimeter Institute for Theoretical Physics

August 30, 2010

PIRSA:10080040
Space-time, Quantum Mechanics and Scattering Amplitudes

Freddy Cachazo
Perimeter Institute for Theoretical Physics

Nima Arkani-Hamed
Institute for Advanced Study (IAS)

August 27, 2010

PIRSA:10080022
Probability of slow roll inflation

Jason Hofgartner
Southwest Research Institute

August 27, 2010

PIRSA:10080039
PSI 2010 - Theoretical Physics - Lecture 5B

Nima Arkani-Hamed
Institute for Advanced Study (IAS)

August 27, 2010

PIRSA:10080037
Space-time, Quantum Mechanics and Scattering Amplitudes - 5A

Freddy Cachazo
Perimeter Institute for Theoretical Physics

Nima Arkani-Hamed
Institute for Advanced Study (IAS)

August 27, 2010

PIRSA:10080017

This mini-course will review recent developments in our understanding of scattering amplitudes in gauge theories, particularly N=4 SYM in four dimensions. We will discuss a dual theory for these scattering amplitudes associated with contour integrals over Grassmannians, where the remarkable symmetries of the theory are manifest, but space-time and unitarity emerge as secondary concepts.

Title	Date	Collection	Type	Info
Quantum Tagging: Authenticating Location via Quantum Information and Relativistic Signalling Constraints	2010‑09‑01	Perimeter Institute Quantum Discussions	Scientific Series	View details
Introduction to Complex Analysis/Computer Skills - Lecture 3B	2010‑09‑01	10/11 PSI - Introduction to Complex Analysis/Computer Skills	Course	View details
Introduction to Complex Analysis/Computer Skills - Lecture 3A	2010‑09‑01	10/11 PSI - Introduction to Complex Analysis/Computer Skills	Course	View details
An Invitation into Eventum Mechanics of Quantum Information	2010‑08‑31	Quantum Foundations	Scientific Series	View details
Introduction to Complex Analysis/Computer Skills - Lecture 2B	2010‑08‑31	10/11 PSI - Introduction to Complex Analysis/Computer Skills	Course	View details
Introduction to Complex Analysis/Computer Skills - Lecture 2A	2010‑08‑31	10/11 PSI - Introduction to Complex Analysis/Computer Skills	Course	View details
Introduction to Complex Analysis/Computer Skills - Lecture 1B	2010‑08‑30	10/11 PSI - Introduction to Complex Analysis/Computer Skills	Course	View details
Introduction to Complex Analysis/Computer Skills - Lecture 1A	2010‑08‑30	10/11 PSI - Introduction to Complex Analysis/Computer Skills	Course	View details
Space-time, Quantum Mechanics and Scattering Amplitudes	2010‑08‑27	Space-time, Quantum Mechanics and Scattering Amplitudes	Course	View details
Probability of slow roll inflation	2010‑08‑27	Summer Undergraduate Research Talks - 2010	Course	View details
PSI 2010 - Theoretical Physics - Lecture 5B	2010‑08‑27	10/11 PSI - Theoretical Physics	Course	View details
Space-time, Quantum Mechanics and Scattering Amplitudes - 5A	2010‑08‑27	Space-time, Quantum Mechanics and Scattering Amplitudes	Course	View details

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