Quantum Information - Review (PHYS 635) - Lecture 9
Daniel Gottesman University of Maryland, College Park
PIRSA:10020041
15829 - 15840 of 20115 Results
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The Robotic Scientist: Mining experimental data for scientific laws, from cognitive robotics to computational biology
Hod Lipson Cornell University
PIRSA:09020048Quantum Gravity - Review (PHYS 638) - Lecture 8
Renate Loll Radboud Universiteit Nijmegen
PIRSA:10020062Quantum Information - Review (PHYS 635) - Lecture 8
Daniel Gottesman University of Maryland, College Park
PIRSA:10020040Purity and reversibility as a paradigm for Quantum Information Processing
Giulio Chiribella University of Hong Kong (HKU)
Foundations and Interpretation of Quantum Theory - Lecture 6 (Part 2 of 2)
Robin Blume-Kohout Sandia National Laboratories
PIRSA:10020081Foundations and Interpretation of Quantum Theory - Lecture 6 (Part 1 of 2)
Robin Blume-Kohout Sandia National Laboratories
PIRSA:10020010Dark Matter: New Data and New Dynamics?
Natalia Toro Stanford University
Quantum Information - Review (PHYS 635) - Lecture 9
Daniel Gottesman University of Maryland, College Park
PIRSA:10020041Week 1: Basic topics (Qubits, quantum gates, quantum circuits, density matrices, quantum operations, entropy, entanglement)Week 2: Algorithms and complexity (Languages, complexity classes, oracles, RSA, Deutsch-Jozsa algorithm, Shor's algorithm, Grover's algorithm)Week 3: Information theory and implementations (Overview of implementations, quantum error correction, quantum cryptography, quantum information theory)The Robotic Scientist: Mining experimental data for scientific laws, from cognitive robotics to computational biology
Hod Lipson Cornell University
PIRSA:09020048For centuries, scientists have attempted to identify analytical laws that underlie physical phenomena in nature. Despite today’s computing power, the process of finding natural laws and their corresponding equations has resisted automation. A key challenge to finding analytic relations automatically – that is, building an autonomous robot - is defining algorithmically what makes a correlation in observed data important and insightful. Scientists are gradually uncovering an ‘alphabet’ that can be used to describe the simplest to most complex physical systems – and by seeking dynamical invariants, researchers go from finding simple predictive models to discovering deeper natural laws. Dr. Lipson will demonstrate the process on a variety of mechanical, biological, and robotic systems.A Computational Grand-Unified Theory
Are Quantum Mechanics and Special Relativity unrelated theories? Is Quantum Field Theory an additional theoretical layer over them? Where the quantization rules and the Plank constant come from? All these questions can find answer in the computational paradigm: "the universe is a huge quantum computer". In my talk I'll take the computational-universe paradigm as genuine theoretical framework, and analyze some relevant implications. A new kind of quantum field theory emerges: "Quantum-Computational Field Theory" (QCFT). I will show how in QCFT Special Relativity unfolds from the fabric of the computational network, which also naturally embeds gauge-invariance, and even the quantization rule and the Planck constant, which thus resort to being properties of the underlying causal tapestry of space-time. In this way Quantum Mechanics remains the only theory needed to describe the computational-universe. I will analyze few simple toy-models in order to explore the mathematical structure of QCFT. The new QCFT has many advantages versus the customary field theoretical framework, solving a number of logical and mathematical problems that plague quantum field theory. One further advantage of QCFT is the possibility of changing the computational engine without changing the field-theoretical framework. One can thus consider different kind of engines, e.g. classical, quantum, super-quantum, and even input-output networks with no pre-established causal relations, which are very interesting for addressing the problem of Quantum Gravity. QCFT opens a large research line: I argue that this program should be addressed soon in the particle physics domain, before entering Quantum Gravity, notwithstanding the experimental success of the usual quantum field theory. It will also be the first test of the Lucien Hardy's program on Quantum Gravity. Reference: arXiv:1001.1088 (http://arxiv.org/abs/1001.1088)
Quantum Gravity - Review (PHYS 638) - Lecture 8
Renate Loll Radboud Universiteit Nijmegen
PIRSA:10020062Quantum Information - Review (PHYS 635) - Lecture 8
Daniel Gottesman University of Maryland, College Park
PIRSA:10020040Week 1: Basic topics (Qubits, quantum gates, quantum circuits, density matrices, quantum operations, entropy, entanglement)Week 2: Algorithms and complexity (Languages, complexity classes, oracles, RSA, Deutsch-Jozsa algorithm, Shor's algorithm, Grover's algorithm)Week 3: Information theory and implementations (Overview of implementations, quantum error correction, quantum cryptography, quantum information theory)Switching boxes connections in operational theories and its consequence on causality
Paolo Perinotti University of Pavia
How can we describe a device that takes two unknown operational boxes and conditionally on some input variable connects them in different orders? In order to answer this question, I will introduce maps from transformations to transformations within operational probabilistic theories with purification, and show their characterisation in terms of operational circuits. I will then proceed exploring the hierarchy of maps on maps. A particular family of maps in the hierarchy are the ones whose output is in the set of transformations. These maps can be fully characterised by their correspondence with channels with memory, and it is exactly the family of transformations that can be implemented through operational circuits. I will then show the problems that arise in defining the remainder of the hierarchy, and the reason why we cannot avoid considering its elements. The main consequence of admitting the generalised transformations as possible within the operational theory is that we cannot describe them in terms of simple causal connection of transformations in a circuit with a fixed causal structure. In quantum theory, we can understand such higher order transformations in terms of superpositions of circuits with different causal structures. The problem whether computations exploiting higher-order transformations can be efficiently simulated by a conventional circuital computer is posed.Quantum Field Theory for Cosmology - Lecture 7
Achim Kempf University of Waterloo
PIRSA:10020014This course begins with a thorough introduction to quantum field theory. Unlike the usual quantum field theory courses which aim at applications to particle physics, this course then focuses on those quantum field theoretic techniques that are important in the presence of gravity. In particular, this course introduces the properties of quantum fluctuations of fields and how they are affected by curvature and by gravitational horizons. We will cover the highly successful inflationary explanation of the fluctuation spectrum of the cosmic microwave background - and therefore the modern understanding of the quantum origin of all inhomogeneities in the universe (see these amazing visualizations from the data of the Sloan Digital Sky Survey. They display the inhomogeneous distribution of galaxies several billion light years into the universe: Sloan Digital Sky Survey).Purity and reversibility as a paradigm for Quantum Information Processing
Giulio Chiribella University of Hong Kong (HKU)
In this talk I will report on a recent work [arXiv:0908.1583], which investigates general probabilistic theories where every mixed state has a purification, unique up to reversible channels on the purifying system. The purification principle is equivalent to the existence of a reversible realization for every physical process, namely that to the fact that every physical process can be regarded as arising from the reversible interaction of the input system with an environment that is eventually discarded. From the purification principle one can also construct an isomorphism between transformations and bipartite states that possesses all structural properties of the Choi-Jamiolkowski isomorphism in Quantum Mechanics. Such an isomorphism allows one to prove most of the basic features of Quantum Information Processing, like e.g. no information without disturbance, no joint discrimination of all pure states, no cloning, teleportation, complementarity between correctable and deletion channels, no programming, and no bit commitment, without resorting to the mathematical framework of Hilbert spaces.Foundations and Interpretation of Quantum Theory - Lecture 6 (Part 2 of 2)
Robin Blume-Kohout Sandia National Laboratories
PIRSA:10020081After a review of the axiomatic formulation of quantum theory, the generalized operational structure of the theory will be introduced (including POVM measurements, sequential measurements, and CP maps). There will be an introduction to the orthodox (sometimes called Copenhagen) interpretation of quantum mechanics and the historical problems/issues/debates regarding that interpretation, in particular, the measurement problem and the EPR paradox, and a discussion of contemporary views on these topics. The majority of the course lectures will consist of guest lectures from international experts covering the various approaches to the interpretation of quantum theory (in particular, many-worlds, de Broglie-Bohm, consistent/decoherent histories, and statistical/epistemic interpretations, as time permits) and fundamental properties and tests of quantum theory (such as entanglement and experimental tests of Bell inequalities, contextuality, macroscopic quantum phenomena, and the problem of quantum gravity, as time permits).Foundations and Interpretation of Quantum Theory - Lecture 6 (Part 1 of 2)
Robin Blume-Kohout Sandia National Laboratories
PIRSA:10020010After a review of the axiomatic formulation of quantum theory, the generalized operational structure of the theory will be introduced (including POVM measurements, sequential measurements, and CP maps). There will be an introduction to the orthodox (sometimes called Copenhagen) interpretation of quantum mechanics and the historical problems/issues/debates regarding that interpretation, in particular, the measurement problem and the EPR paradox, and a discussion of contemporary views on these topics. The majority of the course lectures will consist of guest lectures from international experts covering the various approaches to the interpretation of quantum theory (in particular, many-worlds, de Broglie-Bohm, consistent/decoherent histories, and statistical/epistemic interpretations, as time permits) and fundamental properties and tests of quantum theory (such as entanglement and experimental tests of Bell inequalities, contextuality, macroscopic quantum phenomena, and the problem of quantum gravity, as time permits).Dark Matter: New Data and New Dynamics?
Natalia Toro Stanford University
The quest to understand the nature of dark matter is entering a remarkable data-rich era. Hypothetical stable, electrically neutral particles with TeV-scale mass and weak-strength couplings are a simple, theoretically appealing, but untested candidate for the dark matter. I will summarize recent results in both direct and indirect searches for dark matter, and highlight what upcoming data may teach us. I will also discuss the key role of accelerator-based experiments and novel astrophysical measurements in understanding dark matter and its connection to Standard Model physics. The prospects are particularly rich if dark matter interacts through new, non-Standard-Model dynamics, as recent cosmic-ray data may suggest. I will discuss a range of collider-based searches and fixed-target experiments under development to search for this dynamics, and the complementary sensitivity of searches for cosmic rays originating from dark matter annihilation in the sun.