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Reconstructing quantum states from local data

Isaac Kim University of California, Davis
August 12, 2014

PIRSA:14080007
Condensed Matter
14/15 PSI - Classic Mechanics 1

David Kubiznak Charles University

August 12, 2014

PIRSA:14080009
14/15 PSI - Complex Analysis 1

Tibra Ali Perimeter Institute for Theoretical Physics

August 12, 2014

PIRSA:14080008
Algebraic Geometry in Cosmology

Matilde Marcolli University of Toronto
August 07, 2014

PIRSA:14080002
Cosmology
Criterion for non-Fermi Liquid behavior in a metal with broken symmetry

Ashvin Vishwanath Harvard University
August 06, 2014

PIRSA:14080004
Condensed Matter
Probing the Physics of Active Galaxies Using Multi-wavelength Data

Prajval Shastri Indian Institute of Astrophysics
August 05, 2014

PIRSA:14080000
Cosmology
Uni10 Tensor Network Library

Ying-Jer Kao National Taiwan University
August 05, 2014

PIRSA:14080001
Condensed Matter
Physical Hilbert space for the affine group formulation of 4D, gravity of Lorentzian signature.

Eyo Ita US Naval Academy and Cambridge University (DAMTP)
July 31, 2014

PIRSA:14070033
Quantum Gravity
Asymmetric Hawking Radiation : Baryogenesis from Hawking Radiation

Anson Hook University of Maryland, College Park
July 29, 2014

PIRSA:14070019
Particle Physics
Discussion with Neil Turok

Neil Turok University of Edinburgh

July 24, 2014

PIRSA:14070029
Space-Time Circuit-to-Hamiltonian construction and Its Applications

Barbara Terhal Delft University of Technology
July 23, 2014

PIRSA:14070031
Quantum Foundations
What’s Interesting These Days (With Gravity)?

Latham Boyle University of Edinburgh

July 23, 2014

PIRSA:14070028

Reconstructing quantum states from local data

Isaac Kim University of California, Davis
August 12, 2014

PIRSA:14080007
Condensed Matter
We consider the problem of reconstructing global quantum states from local data. Because the reconstruction problem has many solutions in general, we consider the reconstructed state of maximum global entropy consistent with the local data. We show that unique ground states of local Hamiltonians are exactly reconstructed as the maximal entropy state. More generally, we show that if the state in question is a ground state of a local Hamiltonian with a degenerate space of locally indistinguishable ground states, then the maximal entropy state is close to the ground state projector. We also show that local reconstruction is possible for thermal states of local Hamiltonians. Finally, we discuss a procedure to certify that the reconstructed state is close to the true global state. We call the entropy of our reconstructed maximum entropy state the "reconstruction entropy", and we discuss its relation to emergent geometry in the context of holographic duality. This is a joint work with Brian Swingle.
14/15 PSI - Classic Mechanics 1

David Kubiznak Charles University

August 12, 2014

PIRSA:14080009
14/15 PSI - Complex Analysis 1

Tibra Ali Perimeter Institute for Theoretical Physics

August 12, 2014

PIRSA:14080008
Algebraic Geometry in Cosmology

Matilde Marcolli University of Toronto
August 07, 2014

PIRSA:14080002
Cosmology
The talk is based on joint work with Yuri Manin (arXiv:1402.2158). Using algebro-geometric blowups it is possible to construct a family of models of gluing of aeons across a Big-Bang type singularity, which includes the case of Penrose's conformally cyclic cosmology, as well as inflationary multiverse models generalizing the "eternal symmetree", and BKLL mixmaster type cosmologies. Using the mixmaster dynamics, formulated in terms of elliptic curves and modular curves, we speculate on the geometry of cosmological time near the gluing of aeons. We show also that this type of model allows for phenomena of noncommutativity of spacetime coordinates near the Big-Bang and the crossing of aeons.
Criterion for non-Fermi Liquid behavior in a metal with broken symmetry

Ashvin Vishwanath Harvard University
August 06, 2014

PIRSA:14080004
Condensed Matter
Probing the Physics of Active Galaxies Using Multi-wavelength Data

Prajval Shastri Indian Institute of Astrophysics
August 05, 2014

PIRSA:14080000
Cosmology
Accreting supermassive black holes in the centres of galaxies (i.e. Active Galactic Nuclei - AGN) are now known to play a prominent role in the growth of galaxies through cosmic time. The fundamental parameters to explain the whole range of observed properties of these accreting systems, however, is still elusive. We will present some results from multi-wavelength investigations of the nature of accreting supermassive black holes, including those that produce low kinetic power jets as well as high kinetic power, relativistic jets.
Uni10 Tensor Network Library

Ying-Jer Kao National Taiwan University
August 05, 2014

PIRSA:14080001
Condensed Matter
Physical Hilbert space for the affine group formulation of 4D, gravity of Lorentzian signature.

Eyo Ita US Naval Academy and Cambridge University (DAMTP)
July 31, 2014

PIRSA:14070033
Quantum Gravity
The authors have revealed a fundamental structure which has been hidden within the Wheeler-DeWitt (WDW) constraint of four dimensional General Relativity (GR) of Lorentzian signature in the Ashtekar self-dual variables. The WDW equation can be written as the commutator of two geometric entities, namely the imaginary part of the Chern-Simons functional Q and the local volume element V(x) of 3-space. Upon quantization with cosmological constant, the WDW equation takes on the form of the Lie algebra of the affine group of transformations of the straight line, with Q and V(x) playing the role of the generators for the Lie algebra. The generators are Hermitian, which addresses the issue of the implementation of the reality conditions of GR at the quantum level. Additionally, the irreducible unitary representations (IUR) implement the positivity of the spectrum of the volume operator V(x) at the quantum level This development has led to the existence of elements of the physical Hilbert space for four dimensional gravity of Lorentzian signature, the full theory, in the form of irreducible, unitary representations of the affine group of transformations of the straight line. The affine Lie algebraic structure of the WDW equation remains intact even in the presence of nongravitational fields. This feature has led to the extension of the affine group formulation to elements of the physical Hilbert space for gravity coupled to the full Standard Model of particle physics, quantized on equal footing. Work on the physical interpretation of the states with respect to gauge-diffeomorphism invariant observables, and spacetime geometries solving the Einstein equations is in progress. The journal reference for these results are as follows: - The first result has been published in CQG 30 (2013) 065013 - The second result has just been published in Annals of Physics Journal Vol.343, pages 153-163, April 2014
Asymmetric Hawking Radiation : Baryogenesis from Hawking Radiation

Anson Hook University of Maryland, College Park
July 29, 2014

PIRSA:14070019
Particle Physics
We show that in the presence of a chemical potential, black hole evaporation generates baryon number. If the inflaton or Ricci scalar is derivatively coupled to the B-L current, the expansion of the universe acts as a chemical potential and splits the energy levels of particles and their anti-particles. The asymmetric Hawking radiation of primordial black holes can thus be used to generate a B-L asymmetry. If dark matter is produced by the same mechanism, the coincidence between the mass density of visible and dark matter can be naturally explained.
Discussion with Neil Turok

Neil Turok University of Edinburgh

July 24, 2014

PIRSA:14070029
Space-Time Circuit-to-Hamiltonian construction and Its Applications

Barbara Terhal Delft University of Technology
July 23, 2014

PIRSA:14070031
Quantum Foundations
The circuit-to-Hamiltonian construction translates a dynamics (a quantum circuit and its output) into statics (the groundstate of a circuit Hamiltonian) by explicitly defining a quantum register for a clock. The standard Feynman-Kitaev construction uses one global clock for all qubits while we consider a different construction in which a clock is assigned to each point in space where a qubit of the quantum circuit resides. We show how one can apply this construction to one-dimensional quantum circuits for which the circuit Hamiltonian realizes the dynamics of a vibrating string. We discuss how the construction can be used (1) in quantum complexity theory to obtain new and stronger results in QMA and (2) how one can realize, based on this construction, universal quantum adiabatic computation and a universal quantum walk using a 2D interacting particle Hamiltonian. See http://arxiv.org/abs/1311.6101
What’s Interesting These Days (With Gravity)?

Latham Boyle University of Edinburgh

July 23, 2014

PIRSA:14070028

Many of the most interesting open issues in physics today are related in one way or another to gravity. For the past 100 years, we have described spacetime and gravity via Einstein's theory of "General Relativity." But when we try to mesh General Relativity with the rest of physics, and use it to describe the cosmos, we encounter a range of puzzles. I'll describe some of these puzzles, and some routes to attacking them that look exciting to me.

Title	Date	Collection	Type	Info
Reconstructing quantum states from local data	2014‑08‑12	Quantum Matter	Scientific Series	View details
14/15 PSI - Classic Mechanics 1	2014‑08‑12	14/15 PSI - Front End	Course	View details
14/15 PSI - Complex Analysis 1	2014‑08‑12	14/15 PSI - Front End	Course	View details
Algebraic Geometry in Cosmology	2014‑08‑07	Cosmology and Gravitation	Scientific Series	View details
Criterion for non-Fermi Liquid behavior in a metal with broken symmetry	2014‑08‑06	Quantum Matter	Scientific Series	View details
Probing the Physics of Active Galaxies Using Multi-wavelength Data	2014‑08‑05	Cosmology and Gravitation	Scientific Series	View details
Uni10 Tensor Network Library	2014‑08‑05	Quantum Matter	Other	View details
Physical Hilbert space for the affine group formulation of 4D, gravity of Lorentzian signature.	2014‑07‑31	Quantum Gravity	Scientific Series	View details
Asymmetric Hawking Radiation : Baryogenesis from Hawking Radiation	2014‑07‑29	Particle Physics	Scientific Series	View details
Discussion with Neil Turok	2014‑07‑24	ISSYP 2014		View details
Space-Time Circuit-to-Hamiltonian construction and Its Applications	2014‑07‑23	Perimeter Institute Quantum Discussions	Scientific Series	View details
What’s Interesting These Days (With Gravity)?	2014‑07‑23	ISSYP 2014		View details

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