181,929 research outputs found
Lectures on Gravity and Entanglement
The AdS/CFT correspondence provides quantum theories of gravity in which
spacetime and gravitational physics emerge from ordinary non-gravitational
quantum systems with many degrees of freedom. Recent work in this context has
uncovered fascinating connections between quantum information theory and
quantum gravity, suggesting that spacetime geometry is directly related to the
entanglement structure of the underlying quantum mechanical degrees of freedom
and that aspects of spacetime dynamics (gravitation) can be understood from
basic quantum information theoretic constraints. In these notes, we provide an
elementary introduction to these developments, suitable for readers with some
background in general relativity and quantum field theory. The notes are based
on lectures given at the CERN Spring School 2014, the Jerusalem Winter School
2014, the TASI Summer School 2015, and the Trieste Spring School 2015.Comment: 75 pages, beta version: please e-mail correction
Extension of information geometry for modelling non-statistical systems
In this dissertation, an abstract formalism extending information geometry is
introduced. This framework encompasses a broad range of modelling problems,
including possible applications in machine learning and in the information
theoretical foundations of quantum theory. Its purely geometrical foundations
make no use of probability theory and very little assumptions about the data or
the models are made. Starting only from a divergence function, a Riemannian
geometrical structure consisting of a metric tensor and an affine connection is
constructed and its properties are investigated. Also the relation to
information geometry and in particular the geometry of exponential families of
probability distributions is elucidated. It turns out this geometrical
framework offers a straightforward way to determine whether or not a
parametrised family of distributions can be written in exponential form. Apart
from the main theoretical chapter, the dissertation also contains a chapter of
examples illustrating the application of the formalism and its geometric
properties, a brief introduction to differential geometry and a historical
overview of the development of information geometry.Comment: PhD thesis, University of Antwerp, Advisors: Prof. dr. Jan Naudts and
Prof. dr. Jacques Tempere, December 2014, 108 page
Development of a novel 3D simulation modelling system for distributed manufacturing
This paper describes a novel 3D simulation modelling system for supporting our distributed machine design and control paradigm with respect to simulating and emulating machine behaviour on the Internet. The system has been designed and implemented using Java2D and Java3D. An easy assembly concept of drag-and-drop assembly has been realised and implemented by the introduction of new connection features (unified interface assembly features) between two assembly components (modules). The system comprises a hierarchical geometric modeller, a behavioural editor, and two assemblers. During modelling, designers can combine basic modelling primitives with general extrusions and integrate CAD geometric models into simulation models. Each simulation component (module) model can be visualised and animated in VRML browsers.
It is reusable. This makes machine design re-configurable and flexible. A case study example is given to support our conclusions
Discrete space-time geometry and skeleton conception of particle dynamics
It is shown that properties of a discrete space-time geometry distinguish
from properties of the Riemannian space-time geometry. The discrete geometry is
a physical geometry, which is described completely by the world function. The
discrete geometry is nonaxiomatizable and multivariant. The equivalence
relation is intransitive in the discrete geometry. The particles are described
by world chains (broken lines with finite length of links), because in the
discrete space-time geometry there are no infinitesimal lengths. Motion of
particles is stochastic, and statistical description of them leads to the
Schr\"{o}dinger equation, if the elementary length of the discrete geometry
depends on the quantum constant in a proper way.Comment: 22 pages, 0 figure
Reconstructing Quantum Geometry from Quantum Information: Spin Networks as Harmonic Oscillators
Loop Quantum Gravity defines the quantum states of space geometry as spin
networks and describes their evolution in time. We reformulate spin networks in
terms of harmonic oscillators and show how the holographic degrees of freedom
of the theory are described as matrix models. This allow us to make a link with
non-commutative geometry and to look at the issue of the semi-classical limit
of LQG from a new perspective. This work is thought as part of a bigger project
of describing quantum geometry in quantum information terms.Comment: 16 pages, revtex, 3 figure
The existence of thick triangulations -- an "elementary" proof
We provide an alternative, simpler proof of the existence of thick
triangulations for noncompact manifolds. Moreover, this proof
is simpler than the original one given in \cite{pe}, since it mainly uses tools
of elementary differential topology. The role played by curvatures in this
construction is also emphasized.Comment: 7 pages Short not
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