Gravitational Lensing in an Exact Locally Inhomogeneous Cosmology [microform]

Gravitational Lensing in an Exact Locally Inhomogeneous Cosmology [microform] PDF Author: Attard, Allen
Publisher: Library and Archives Canada = Bibliothèque et Archives Canada
ISBN: 9780494075739
Category :
Languages : en
Pages : 398

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Book Description
A Recursive Swiss-Cheese (RSC) cosmological model is an exact solution to Einstein's general relativistic field equations allowing for dramatic local density inhomogeneities while maintaining global homogeneity and isotropy. It is constructed by replacing spherical regions of an FRW background with higher density cores placed at the centre of a Schwarzschild vacuum, with each core itself potentially being given the same treatment and the process repeated to generate a range of multifractal structures. Code was developed to tightly pack spheres into spaces of constant curvature in an efficient manner, and was used to develop libraries of packings with positive, negative, and zero curvature. Various projections are used to illustrate their structure, and means of measuring its dimensionality are discussed. A method by which these packings can be used as building blocks of an RSC model, along with a way of selecting parameters to define the model, is described, and a coordinate system allowing a relativistically consistent means of synchronizing its various components is developed. Formulations of the optical scalar equations for the expansion and shear rates of a beam are considered, and a set suitable for numerical integration selected. The forms of the null geodesic beam trajectories in each region of the model are computed, and a parallel propagated shadow plane basis that can be consistently followed between the various model sections is established. This allowed the development of code using a fourth order, variable step size Runge-Kutta integration routine to compute the gravitational lensing effect within an RSC model by tracking the amplification and distortion of a series of beams that are propagated through it. The output generated allows the redshift evolution of these quantities to be plotted for each beam, and enables maps to be made of the "observed sky". The amplification signature produced by a single lens in the model is examined, and the form shown to be generally consistent with that found using a thin lens approximation, particularly when the lensing is weak. Distortion values are likewise shown to be reasonable, and results derived from propagating beams through a full RSC model are also presented.

Gravitational Lensing in an Exact Locally Inhomogeneous Cosmology [microform]

Gravitational Lensing in an Exact Locally Inhomogeneous Cosmology [microform] PDF Author: Attard, Allen
Publisher: Library and Archives Canada = Bibliothèque et Archives Canada
ISBN: 9780494075739
Category :
Languages : en
Pages : 398

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Book Description
A Recursive Swiss-Cheese (RSC) cosmological model is an exact solution to Einstein's general relativistic field equations allowing for dramatic local density inhomogeneities while maintaining global homogeneity and isotropy. It is constructed by replacing spherical regions of an FRW background with higher density cores placed at the centre of a Schwarzschild vacuum, with each core itself potentially being given the same treatment and the process repeated to generate a range of multifractal structures. Code was developed to tightly pack spheres into spaces of constant curvature in an efficient manner, and was used to develop libraries of packings with positive, negative, and zero curvature. Various projections are used to illustrate their structure, and means of measuring its dimensionality are discussed. A method by which these packings can be used as building blocks of an RSC model, along with a way of selecting parameters to define the model, is described, and a coordinate system allowing a relativistically consistent means of synchronizing its various components is developed. Formulations of the optical scalar equations for the expansion and shear rates of a beam are considered, and a set suitable for numerical integration selected. The forms of the null geodesic beam trajectories in each region of the model are computed, and a parallel propagated shadow plane basis that can be consistently followed between the various model sections is established. This allowed the development of code using a fourth order, variable step size Runge-Kutta integration routine to compute the gravitational lensing effect within an RSC model by tracking the amplification and distortion of a series of beams that are propagated through it. The output generated allows the redshift evolution of these quantities to be plotted for each beam, and enables maps to be made of the "observed sky". The amplification signature produced by a single lens in the model is examined, and the form shown to be generally consistent with that found using a thin lens approximation, particularly when the lensing is weak. Distortion values are likewise shown to be reasonable, and results derived from propagating beams through a full RSC model are also presented.

Literature 1992, Part 1

Literature 1992, Part 1 PDF Author: Astronomisches Recheninstitut
Publisher: Springer Science & Business Media
ISBN: 3662123797
Category : Science
Languages : en
Pages : 1456

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Book Description
"Astronomy and Astrophysics Abstracts" appearing twice a year has become oneof the fundamental publications in the fields of astronomy, astrophysics andneighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. The abstracts are classified under more than a hundred subject categories, thus permitting a quick survey of the whole extended material. The AAA is a valuable and important publication for all students and scientists working in the fields of astronomy and related sciences. As such it represents a necessary ingredient of any astronomical library all over the world.

Gravitational Lensing: Strong, Weak and Micro

Gravitational Lensing: Strong, Weak and Micro PDF Author: Peter Schneider
Publisher: Springer Science & Business Media
ISBN: 3540303103
Category : Science
Languages : en
Pages : 565

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Book Description
The observation, in 1919 by A.S. Eddington and collaborators, of the gra- tational de?ection of light by the Sun proved one of the many predictions of Einstein’s Theory of General Relativity: The Sun was the ?rst example of a gravitational lens. In 1936, Albert Einstein published an article in which he suggested - ing stars as gravitational lenses. A year later, Fritz Zwicky pointed out that galaxies would act as lenses much more likely than stars, and also gave a list of possible applications, as a means to determine the dark matter content of galaxies and clusters of galaxies. It was only in 1979 that the ?rst example of an extragalactic gravitational lens was provided by the observation of the distant quasar QSO 0957+0561, by D. Walsh, R.F. Carswell, and R.J. Weymann. A few years later, the ?rst lens showing images in the form of arcs was detected. The theory, observations, and applications of gravitational lensing cons- tute one of the most rapidly growing branches of astrophysics. The gravi- tional de?ection of light generated by mass concentrations along a light path producesmagni?cation,multiplicity,anddistortionofimages,anddelaysp- ton propagation from one line of sight relative to another. The huge amount of scienti?c work produced over the last decade on gravitational lensing has clearly revealed its already substantial and wide impact, and its potential for future astrophysical applications.

Astroparticle Physics

Astroparticle Physics PDF Author: Claus Grupen
Publisher: Springer Nature
ISBN: 3030273393
Category : Science
Languages : en
Pages : 616

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Book Description
Describes the branch of astronomy in which processes in the universe are investigated with experimental methods employed in particle-physics experiments. After a historical introduction the basics of elementary particles, Explains particle interactions and the relevant detection techniques, while modern aspects of astroparticle physics are described in a chapter on cosmology. Provides an orientation in the field of astroparticle physics that many beginners might seek and appreciate because the underlying physics fundamentals are presented with little mathematics, and the results are illustrated by many diagrams. Readers have a chance to enter this field of astronomy with a book that closes the gap between expert and popular level.

Relativity and Scientific Computing

Relativity and Scientific Computing PDF Author: Friedrich W Hehl
Publisher: Springer
ISBN: 9783642957345
Category : Science
Languages : en
Pages : 389

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Book Description
For this set of lectures we assumed that the reader has a reasonable back ground in physics and some knowledge of general relativity, the modern theory of gravity in macrophysics, and cosmology. Computer methods are present ed by leading experts in the three main domains: in numerics, in computer algebra, and in visualization. The idea was that each of these subdisciplines is introduced by an extended set of main lectures and that each is conceived as being of comparable 'importance. Therefpre we believe that the book represents a good introduction into scientific I computing for any student who wants to specialize in relativity, gravitation, and/or astrophysics. We took great care to select lecturers who teach in a comprehensible way and who are, at the same time, at the research front of their respective field. In numerics we had the privilege of having a lecturer from the National Center for Supercomputing Applications (NCSA, Champaign, IL, USA) and some from other leading institutions of the world; visualization was taught by a visualization expert from Boeing; and in com puter algebra we took recourse to practitioners of different computer algebra systems as applied to classical general relativity up to quantum gravity and differential geometry.

Physics Briefs

Physics Briefs PDF Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 914

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Book Description


The Physics of Ultra-High-Density Magnetic Recording

The Physics of Ultra-High-Density Magnetic Recording PDF Author: M.L. Plumer
Publisher: Springer Science & Business Media
ISBN: 364256657X
Category : Science
Languages : en
Pages : 364

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Book Description
Application-oriented book on magnetic recording, focussing on the underlying physical mechanisms that play crucial roles in medium and transducer development for high areal density disk drives.

Elements of Quantum Optics

Elements of Quantum Optics PDF Author: Pierre Meystre
Publisher: Springer Science & Business Media
ISBN: 3662038773
Category : Science
Languages : en
Pages : 432

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Book Description
From the reviews: "This is a book that should be found in any physics library. It is extremely useful for all graduate students, Ph.D. students and researchers interested in the quantum physics of light." Optics & Photonics News

Observational Astrophysics

Observational Astrophysics PDF Author: Pierre Lena
Publisher: Springer Science & Business Media
ISBN: 366202554X
Category : Science
Languages : en
Pages : 338

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Book Description
For the last twenty years astronomy has been developing dramatically. Until the nineteen-fifties, telescopes, spectrometers, and photographic plates consti tuted a relatively simple set of tools which had been refined to a high degree of perfection by the joint efforts of physicists and astronomers. Indeed these tools helped at the birth of modern astrophysics: the discovery of the expan sion of the Universe. Then came radioastronomy and the advent of electronics; the last thirty years have seen the application to astrophysics of a wealth of new experimental techniques, based on the most advanced fields of physics, and a constant interchange of ideas between physicists and astronomers. Last, but not least, modern computers have sharply reduced the burden of dealing with the information painfully extracted from the skies, whether from ever scarce photons, or from the gigantic data flows provided by satellites and large telescopes. The aim of this book is not to give an extensive overview of all the tech niques currently in use in astronomy, nor to provide detailed instructions for preparing or carrying out an astronomical project. Its purpose is methodologi cal: photons are still the main carriers of information between celestial sources and the observer. How we are to collect, sample, measure, and store this infor mation is the unifying theme of the book. Rather than the diversity of tech niques appropriate for each wavelength range, we emphasize the physical and mathematical bases which are common to all wavelength regimes.

INIS Atomindex

INIS Atomindex PDF Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 872

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Book Description