Weak Gravitational Lensing of Large Scale Structures PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Weak Gravitational Lensing of Large Scale Structures PDF full book. Access full book title Weak Gravitational Lensing of Large Scale Structures by Chukwuemeka Martins Asogwa. Download full books in PDF and EPUB format.
Author: Chukwuemeka Martins Asogwa
Publisher: LAP Lambert Academic Publishing
ISBN: 9783659798481
Category :
Languages : en
Pages : 76
Get Book Here
Book Description
Weak gravitational lensing refers to very small distortions of images of background sources (for example galaxies) near a foreground mass (an object which lie between the source and the observer). This effect is studied through coordinate transformation which relates the source coordinate to image coordinate. The derivatives of this transformation is decomposed into trace (convergence) and trace-free part (shear). The trace part magnifies the background sources by increasing their size, and the trace-free part stretches them tangentially with respect to the foreground mass. This book aims to go beyond the usual point source approximation to study the effect of lensing of light from a finite source, which corresponds to lensing of the large scale structures in the universe
Author: Chukwuemeka Martins Asogwa
Publisher: LAP Lambert Academic Publishing
ISBN: 9783659798481
Category :
Languages : en
Pages : 76
Get Book Here
Book Description
Weak gravitational lensing refers to very small distortions of images of background sources (for example galaxies) near a foreground mass (an object which lie between the source and the observer). This effect is studied through coordinate transformation which relates the source coordinate to image coordinate. The derivatives of this transformation is decomposed into trace (convergence) and trace-free part (shear). The trace part magnifies the background sources by increasing their size, and the trace-free part stretches them tangentially with respect to the foreground mass. This book aims to go beyond the usual point source approximation to study the effect of lensing of light from a finite source, which corresponds to lensing of the large scale structures in the universe
Author: Marc Gentile
Publisher:
ISBN:
Category :
Languages : en
Pages : 196
Get Book Here
Book Description
Author: Frederic Courbin
Publisher: Springer
ISBN: 3540458573
Category : Science
Languages : en
Pages : 202
Get Book Here
Book Description
Gravitational lensing is by now sufficiently well understood that it can be used as a tool of investigation in other astrophysical areas. Applications include the determination of the Hubble constant, probing the dark matter context of galaxies and the mapping of the universe to the identification of otherwise invisible large-scale structures. Each chapter of the book covers in a self-contained manner a subfield of gravitational lensing, with the double aim of describing in a simple way the basics of the theory and of reviewing the most recent developments as well as applications foreseen in the near future. The book will thus be particularly useful as a high-level textbook for nonspecialist researchers and advanced students wishing to become familiar with the field all the way up to the forefront of research.
Author: Tzu-Ching Chang
Publisher:
ISBN:
Category :
Languages : en
Pages : 242
Get Book Here
Book Description
Author: Malin Nicole Renneby
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Author: Jens Verner Villumsen
Publisher:
ISBN:
Category :
Languages : de
Pages : 10
Get Book Here
Book Description
Author: Silvia Mollerach
Publisher: World Scientific
ISBN: 9814489352
Category : Science
Languages : en
Pages : 204
Get Book Here
Book Description
This book provides a comprehensive and self-contained exposition of gravitational lensing phenomena. It presents the up-to-date status of gravitational lensing and microlensing, covering the cosmological applications of the observed lensing by galaxies, clusters and the large scale structures, as well as the microlensing searches in the Local Group and its applications to unveil the nature of the galactic dark matter, the search for planetary objects and the distribution of faint stars in our galaxy.Gravitational Lensing and Microlensing is pitched at the level of the graduate student interested in the issues of astrophysics and cosmology, and should be useful for specialist researchers as well.
Author: Evencio Mediavilla
Publisher: Cambridge University Press
ISBN: 1316684040
Category : Science
Languages : en
Pages : 305
Get Book Here
Book Description
Gravitational lenses offer the best, and sometimes the only, means of tackling key problems in many fields of astrophysics and cosmology. According to Einstein's theory, the curvature of light-rays increases with mass; gravitational lenses can be used to map the distribution of mass in a Universe in which virtually all matter is dark matter of an unknown nature. Gravitational lensing has significantly improved our knowledge of many astrophysical phenomena, such as exoplanets, galaxies, active galactic nuclei, quasars, clusters, large-scale structure and the Universe itself. All these topics are covered fully in this book, together with two tutorials on lens and microlensing modelling. The future of lensing in relation to large surveys and the anticipated discoveries of thousands more gravitational lenses is also discussed, making this volume an ideal guide for postgraduate students and practising researchers in the use of gravitational lenses as a tool in their investigations.
Author: Tingting Lu
Publisher:
ISBN: 9780494776056
Category :
Languages : en
Pages : 294
Get Book Here
Book Description
Dark matter dominates the mass distribution of the universe, and dark energy determines its expansion. The two are the most mysterious and attractive subjects in modern cosmology, because they provide an opportunity to discover new fundamental physics.Cosmological weak gravitational lensing, which describes the deflection of photons by the gravitational force from large-scale structure in the universe, has been an active area of research in the past decade with many completed, ongoing, and upcoming surveys. Because weak lensing is sensitive to the growth of structure and expansion history of the universe, it is a great tool for improving our understanding of both dark matter and dark energy problems.We show that the non-Gaussianity nature of lensing decreases the dark energy figure of merit by a factor of 1.3 to 1.6 for a few future surveys. We also find that the non-Gaussianity nature of the 21-cm sources reduces the signal to noise ratio by several orders of magnitude. The reconstruction noise saturates at mildly non-linear scales, where the linear power spectrum of the source is Delta2 ∼ 0.2 -- 0.5. For 21-cm sources at z ∼ 2 -- 4, the lensing reconstruction is limited by cosmic variance at ℓ ≲ 100, which is in the linear regime of gravitational growth, and robustly predicted by theory. This allows promising constraints to various modified gravity and dark energy models.Cosmic structures have become non-linear by gravitational clustering. The non-linear structures are important to weak lensing, and cause non-Gaussianity in the lensing maps. In this thesis, I study the influence of non-linearity and non-Gaussianity on the uncertainty of lensing measurements. I develop a new method to robustly measure the co-variance matrix of the lensing convergence power spectrum, from simulations. Because 21-cm intensity map may soon cover half sky at redshift 1-4, I build optimal estimators for reconstructing lensing from the 21-cm sources. I develop Gaussian optimal estimators which can be derived analytically, and non-Gaussian optimal estimators which can be constructed numerically from simulation data. I then run a large number of N-body simulations. For both lenses and 21-cm sources, I explore the statistical uncertainties in the simulation data.
Author: Massimo Meneghetti
Publisher: Springer Nature
ISBN: 3030735826
Category : Science
Languages : en
Pages : 412
Get Book Here
Book Description
This book introduces the phenomenology of gravitational lensing in an accessible manner and provides a thorough discussion of the related astrophysical applications. It is intended for advanced undergraduates and graduate students who want to start working in this rapidly evolving field. This includes also senior researchers who are interested in ongoing or future surveys and missions such as DES, Euclid, WFIRST, LSST. The reader is guided through many fascinating topics related to gravitational lensing like the structure of our galaxy, the searching for exoplanets, the investigation of dark matter in galaxies and galaxy clusters, and several aspects of cosmology, including dark energy and the cosmic microwave background. The author, who has gained valuable experience as academic teacher, guides the readers towards the comprehension of the theory of gravitational lensing and related observational techniques by using simple codes written in python. This approach, beyond facilitating the understanding of gravitational lensing, is preparatory for learning the python programming language which is gaining large popularity both in academia and in the private sector.
