176,470 research outputs found
Formal Analysis of Geometrical Optics using Theorem Proving
Geometrical optics is a classical theory of Physics which describes the light propagation in the form of rays and beams.
One of its main advantages is efficient and scalable formalism for the modeling and analysis of a variety of optical
systems which are used in ubiquitous applications including telecommunication, medicine and biomedical devices.
Traditionally, the modeling and analysis of optical systems have been carried out by paper-and-pencil based proofs and
numerical algorithms. However, these techniques cannot provide perfectly accurate results due to the risk of human
error and inherent incompleteness of numerical algorithms. In this thesis, we propose a higher-order logic theorem
proving based framework to analyze optical systems. The main advantages of this framework are the expressiveness
of higher-order logic and the soundness of theorem proving systems which provide unrivaled analysis accuracy.
In particular, this thesis provides the higher-order logic formalization of geometrical optics including the notion of
light rays, beams and optical systems. This allows us to develop a comprehensive analysis support for optical resonators,
optical imaging and Quasi-optical systems. This thesis also facilitates the verification of some of the most interesting
optical system properties like stability, chaotic map generation, beam transformation and mode analysis. We use this
infrastructure to build a library of commonly used optical components such as lenses, mirrors and optical cavities.
In order to demonstrate the effectiveness of our proposed approach, we conduct the formal analysis of some
real-world optical systems, e.g., an ophthalmic device for eye, a Fabry-P\'{e}rot resonator, an optical
phase-conjugated ring resonator and a receiver module of the APEX telescope. All the above mentioned work is
carried out in the HOL Light theorem prover
Formal Analysis of Quantum Optics
At the beginning of the last century, the theory of quantum optics arose and led to a revolution in physics, since it allowed the interpretation of many unknown phenomena and the development of numerous powerful, cutting edge engineering applications,
such as high precision laser technology. The analysis and verification of such applications and systems, however, are very complicated. Moreover, traditional analysis tools, e.g., simulation, numerical methods, computer algebra systems, and paper-and-pencil approaches are not well suited for quantum systems. In the last decade, a new emerging verification technique, called formal methods, became common among engineering domains, and has proven to be effective as an analysis tool. Formal methods
consist in the development of mathematical models of the system subject for analysis, and deriving computer-aided mathematical proofs. In this thesis, we propose a framework for the analysis of quantum optics based on formal methods, in particular theorem proving. The framework aims at implementing necessary quantum mechanics and optics concepts and theorems that facilitate the modelling of quantum optical devices and circuits, and then reason about them formally. To this end, the framework
consists of three major libraries: 1) Mathematical foundations, which mainly contain the theory of complex-valued-function linear spaces, 2) Quantum mechanics, which develops the general rules of quantum physics, and 3) Quantum Optics, which
specializes these rules for light beams and implements all related concepts, e.g., light coherence which is typically emitted by laser sources. On top of these theoretical foundations, we build a library of formal models of a number of optical devices commonly
used in quantum circuits, including, beam splitters, light displacers, and light phase shifters. Using the proposed framework, we have been able to formally verify common quantum optical computing circuits, namely the Flip gate, CNOT gate, and Mach-Zehnder interferometer
UV Imaging of the Galaxy Cluster CL0939+4713 (Abell 851) at z=0.41
The first UV F300W and F218W WFPC2 observations of the rich galaxy cluster
CL0939+4713 at z=0.41 are presented and discussed. UV/optical two-color and c-m
diagrams of the sources detected in the F300W waveband are constructed. Thanks
to pre-existing HST optical images of the same field a morphological
classification for the majority of these objects is also provided. Moreover,
taking advantage of recent redshift surveys along CL0939+4713 line of sight,
separate diagrams comparing the properties of galaxies belonging to the cluster
and to its close projected field are presented. Possible evolutionary effects
in the UV from z~0.4 to present time are investigated by comparing the
restframe [mid-UV-Optical] colors of galaxies in CL0939+4713 with balloon-borne
data of the Coma cluster, as well as by resorting to suitable galaxy evolution
models. Finally, current attempts to constrain the epoch of the UV-upturn onset
in evolved populations by means of HST UV observations are discussed.Comment: 20 pages, LaTeX, with 6 PostScript figures, Submitted to The
Astrophysical Journal, Figures 1 and 2 have lower resolution than the ApJ
submitted versio
Maunakea Spectroscopic Explorer Advancing from Conceptual Design
The Maunakea Spectroscopic Explorer (MSE) project has completed its
Conceptual Design Phase. This paper is a status report of the MSE project
regarding its technical and programmatic progress. The technical status
includes its conceptual design and system performance, and highlights findings
and recommendations from the System and various subsystems design reviews. The
programmatic status includes the project organization and management plan for
the Preliminary Design Phase. In addition, this paper provides the latest
information related to the permitting process for Maunakea construction.Comment: 15 pages; Proceedings of SPIE Astronomical Telescopes +
Instrumentation 2018; Ground-based and Airborne Telescopes VI
BeamOptics: a Symbolic Platform for Modeling and the Solution of Beam Optics System
BeamOptics [1] is a Mathematica-based computing platform devoted to the following objectives; · Structured representation and manipulation of particle beam optics systems with symbolic capabilities, · Analytical and numerical modeling of beam optics system behaviors, · Solution to specific beam optical or general accelerator system problems, in algebraic form in certain cases, through customized algorithms. Taking advantage of and conforming to the highly formal and self-contained structure of Mathematica, BeamOptics provides a unique platform for developing accelerator design and analysis programs. The feature of symbolic computation and the ability to manipulate the beam optics system at the programming language level enable the user to solve or optimize his system with considerably more efficiency, rigour and insight than can be easily achieved with passive modeling or numerical simulation methods. BeamOptics is developed with continuous evolution in mind. New features and algorithms from diverse sources can be incorporated without major modification, due to its formal and generic structure. In this report, a survey is given of the basic structure and methodology of BeamOptics, as well as a demonstration of some of its more specialized applications, and possible direction of evolution
A Search for Rapid Photometric Variability in Symbiotic Binaries
We report on our survey for rapid (time scale of minutes) photometric
variability in symbiotic binaries. These binaries are becoming an increasingly
important place to study accretion onto white dwarfs since they are candidate
Type Ia supernovae progenitors. Unlike in most cataclysmic variables, the white
dwarfs in symbiotics typically accrete from a wind, at rates greater than or
equal to 10^{-9} solar masses per year. In order to elucidate the differences
between symbiotics and other white dwarf accretors, as well as search for
magnetism in symbiotic white dwarfs, we have studied 35 primarily northern
symbiotic binaries via differential optical photometry. Our study is the most
comprehensive to date of rapid variability in symbiotic binaries. We have found
one magnetic accretor, Z And, previously reported by Sokoloski & Bildsten
(1999). In four systems (EG And, BX Mon, CM Aql, and BF Cyg), some evidence for
flickering at a low level (roughly 10 mmag) is seen for the first time. These
detections are, however, marginal. For 25 systems, we place tight upper limits
(order of mmag) on both aperiodic and periodic variability, highlighting a
major difference between symbiotics and cataclysmic variables. The remaining
five of the objects included in our sample (the 2 recurrent novae RS Oph and T
CrB, plus CH Cyg, o Ceti, and MWC 560) had previous detections of
large-amplitude optical flickering, and we present our extensive observations
of these systems in a separate paper. We discuss the impact of our results on
the ``standard'' picture of wind-fed accretion, and speculate on the
possibility that in most symbiotics, light from quasi-steady nuclear burning on
the surface of the white dwarf hides the fluctuating emission from accretion.Comment: 24 pages, 17 figures. Submitted to MNRAS (12/21/00), and revised in
response to referee comments (3/30/01
Energy-transport systems for optical lattices: derivation, analysis, simulation
Energy-transport equations for the transport of fermions in optical lattices
are formally derived from a Boltzmann transport equation with a periodic
lattice potential in the diffusive limit. The limit model possesses a formal
gradient-flow structure like in the case of the energy-transport equations for
semiconductors. At the zeroth-order high temperature limit, the
energy-transport equations reduce to the whole-space logarithmic diffusion
equation which has some unphysical properties. Therefore, the first-order
expansion is derived and analyzed. The existence of weak solutions to the
time-discretized system for the particle and energy densities with periodic
boundary conditions is proved. The difficulties are the nonstandard degeneracy
and the quadratic gradient term. The main tool of the proof is a result on the
strong convergence of the gradients of the approximate solutions. Numerical
simulations in one space dimension show that the particle density converges to
a constant steady state if the initial energy density is sufficiently large,
otherwise the particle density converges to a nonconstant steady state
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