Download or read book The Hubble Constant and the lambda CDM Cosmology A Magnified View Using Strong Lensing written by Anowar Jaman Shajib and published by . This book was released on 2020 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, a significant tension has been reported between two measurements of the Hubble constant (H_0) from early-Universe (e.g., cosmic microwave background) and late-Universe probes (e.g., cosmic distance ladder). If systematic errors are ruled out in these measurements, then new physics extending the CDM model will be required to resolve the tension. Therefore, different independent probes of H_0 -- such as the strong-lensing time-delay -- are essential to confirm or resolve the tension. The measured time-delays between the lensed images of a background quasar constrain H_0, as they depend on the absolute physical distances in the lens configuration. I led a team from the STRong-lensing Insights into the Dark Energy Survey (STRIDES) collaboration to analyze the lens DES J0408-5354. I modeled the mass distribution of this lens using Hubble Space Telescope imaging, and combined it with analyses from my collaborators to infer H_0 = 74.2-3.0+2.7 km s^-1 Mpc^-1 with the highest precision (3.9 per cent) from a single lens to date. This measurement agrees well with both the previous sample of six lenses from the H0LiCOW collaboration and other late-Universe probes, thus it increases the aforementioned tension. To confirm or resolve this tension at the 5 level -- the gold standard of detecting new physics -- we need to increase the sample size and improve precision per system while keeping the systematics under control. The large amount of required investigator time (~1 year per lens) is currently the main bottleneck to increase the sample size. I present an automated lens-modeling framework that will enable rapid increment of the sample size in the near future. I also show, through simulation, that incorporating the spatially resolved kinematics of the lensing galaxy improves the precision of H_0 per system. Additionally, I develop the first general method to efficiently compute the lensing properties of any given elliptical mass distribution. By allowing any radial shape of mass profile, this method helps to avoid any systematic that may potentially arise from adopting only a few specific parameterizations. I forecast that a sample of ~40 lenses with spatially resolved kinematics will provide sub-per-cent precision in H_0 within the next decade.
Download or read book A Different Approach to Cosmology written by F. Hoyle and published by Cambridge University Press. This book was released on 2000-02-17 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a different kind of book about cosmology, a field of major interest to professional astronomers, physicists, and the general public. All research in cosmology adopts one model of the universe, the hot big bang model. But Fred Hoyle, Geoffrey Burbidge and Jayant Narlikar take a different approach. Starting with the beginnings of modern cosmology, they then conduct a wide ranging and deep review of the observations made from 1945 to the present day. Here they challenge many conventional interpretations. The latter part of the book presents the authors' own account of the present status of observations and how they should be explained. The controversial theme is that the dependency on the hot big bang model has led to an unwarranted rejection of alternative cosmological models. Writing from the heart, with passion and punch, these three cosmologists make a powerful case for viewing the universe in a different light.
Download or read book Gravity s Lens written by Nathan Cohen and published by . This book was released on 1988-07-11 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: A highly readable and entertaining guide to modern cosmology. Brings to life new discoveries in the farthest reaches of space, making astronomy accessible to the general reader. Discusses, in nontechnical language, cosmic strings, inflationary models of the early universe, the superstring theory, quasars, galactic streamers, superluminal jets, and gravitational lenses. Building from an historical perspective, the author describes exotic celestial phenomena, and explains the latest theories of the birth and death of the universe.
Download or read book Gravitational Dynamics of Halo Formation in a Collisional Versus Collisionless Cold Dark Matter Universe written by Jun Koda and published by . This book was released on 2009 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flat cosmology with collisionless cold dark matter (CDM) and cosmological constant ([Lambda]CDM cosmology) may have some problems on small scales, even though it has been very successful on large scales. We study the effect of Self-Interacting Dark Matter (SIDM) hypothesis on the density profiles of halos. Collisionless CDM predicts cuspy density profiles toward the center, while observations of low mass galaxies prefer cored profiles. SIDM was proposed by Spergel & Steinhardt [161] as a possible solution to this cuspy profile problem on low-mass scales. On the other hand, observations and collisionless CDM agree on mass scales of galaxy clusters. It is also known that the SIDM hypothesis would contradict with X-ray and gravitational lensing observations of cluster of galaxies, if the cross section were too large. Our final goal is to find the range of SIDM scattering cross section models that are consistent with those astrophysical observations in two different mass scales. There are two theoretical approaches to compute the effect of self-interacting scattering -- Gravitational N-body simulation with Monte Carlo scattering and conducting fluid model; those two approaches, however, had not been confirmed to agree with each other. We first show that two methods are in reasonable agreement with each other for both isolated halos and for halos with realistic mass assembly history in an expanding [Lambda]CDM universe; the value of cross section necessary to have a maximally relaxed low-density core in [Lambda]CDM is in mutual agreement. We then develop a semianalytic model that predicts the time evolution of SIDM halo. Our semianalytic relaxation model enables us to understand how a SIDM halo would relax to a cored profile, and obtain an ensemble of SIDM halos from collisionless simulations with reasonable computational resources. We apply the semianalytic relaxation model to CDM halos, and compare the resulting statistical distribution of SIDM halos with astrophysical observations. We show that there exists a range of scattering cross sections that simultaneously solve the cuspy core problem on low-mass scales and satisfy the galaxy cluster observations. We also present that other potential conflicts between [Lambda]CDM and observations could be resolved in Part II and III.
Download or read book Dark Energy written by Luca Amendola and published by Cambridge University Press. This book was released on 2010-06-10 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introducing the theoretical ideas, observational methods and results in dark energy, this textbook is a thorough introduction to dark energy for graduate courses.
Download or read book Formation of Structure in the Universe written by Avishai Dekel and published by Cambridge University Press. This book was released on 1999-04-15 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: This advanced textbook provides an up-to-date and comprehensive introduction to the very active field of structure formation in cosmology. It is written by eleven world-leading authorities. Written in a clear and pedagogical style appropriate for graduate students in astronomy and physics, this textbook introduces the reader to a wide range of exciting topics in contemporary cosmology: from recent advances in redshift surveys, to the latest models in gravitational lensing and cosmological simulations. The authors are all world-renowned experts both for their research and teaching skills. In the fast-moving field of structure formation, this book provides advanced undergraduate and graduate students with a welcome textbook which unites the latest theory and observations.
Download or read book The Cosmic Microwave Background written by C.H. Lineweaver and published by Springer. This book was released on 2011-09-20 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Study Institute on the Cosmological Background Radiation, Strasbourg, France, May 27-June 7, 1996
Download or read book Modern Cosmology written by Scott Dodelson and published by Academic Press. This book was released on 2003-03-13 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: An advanced text for senior undergraduates, graduate students and physical scientists in fields outside cosmology. This is a self-contained book focusing on the linear theory of the evolution of density perturbations in the universe, and the anisotropiesin the cosmic microwave background.
Download or read book The Oxford Handbook of Philosophy of Physics written by Robert Batterman and published by Oxford University Press. This book was released on 2013-03-14 with total page 701 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Oxford Handbook provides an overview of many of the topics that currently engage philosophers of physics. It surveys new issues and the problems that have become a focus of attention in recent years. It also provides up-to-date discussions of the still very important problems that dominated the field in the past. In the late 20th Century, the philosophy of physics was largely focused on orthodox Quantum Mechanics and Relativity Theory. The measurement problem, the question of the possibility of hidden variables, and the nature of quantum locality dominated the literature on the quantum mechanics, whereas questions about relationalism vs. substantivalism, and issues about underdetermination of theories dominated the literature on spacetime. These issues still receive considerable attention from philosophers, but many have shifted their attentions to other questions related to quantum mechanics and to spacetime theories. Quantum field theory has become a major focus, particularly from the point of view of algebraic foundations. Concurrent with these trends, there has been a focus on understanding gauge invariance and symmetries. The philosophy of physics has evolved even further in recent years with attention being paid to theories that, for the most part, were largely ignored in the past. For example, the relationship between thermodynamics and statistical mechanics—-once thought to be a paradigm instance of unproblematic theory reduction—-is now a hotly debated topic. The implicit, and sometimes explicit, reductionist methodology of both philosophers and physicists has been severely criticized and attention has now turned to the explanatory and descriptive roles of "non-fundamental,'' phenomenological theories. This shift of attention includes "old'' theories such as classical mechanics, once deemed to be of little philosophical interest. Furthermore, some philosophers have become more interested in "less fundamental'' contemporary physics such as condensed matter theory. Questions abound with implications for the nature of models, idealizations, and explanation in physics. This Handbook showcases all these aspects of this complex and dynamic discipline.
Download or read book Neutrino Cosmology written by Julien Lesgourgues and published by Cambridge University Press. This book was released on 2013-02-21 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: A self-contained guide to the role played by neutrinos in the Universe and how their properties influence cosmological and astrophysical observations.
Download or read book Introduction to Gravitational Lensing written by Massimo Meneghetti and published by Springer Nature. This book was released on 2021-12-10 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Relativity Gravitation and Cosmology written by Ta-Pei Cheng and published by Oxford University Press. This book was released on 2010 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to Einstein's general theory of relativity, this work is structured so that interesting applications, such as gravitational lensing, black holes and cosmology, can be presented without the readers having to first learn the difficult mathematics of tensor calculus.
Download or read book Clusters and Superclusters of Galaxies written by A.C. Fabian and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clusters and superclusters of galaxies are the largest objects in the Universe. They have been the subject of intense observational studies at a variety of wavelengths, from radio to X-ray which has provoked much theoretical debate and advanced our understanding of the recent evolution of the large-scale structure of the Universe. The current status of the subject is reviewed in this volume by active researchers who lectured at a NATO Advanced Study Institute held in Cambridge, England in July 1991. Much of the material is presented in a pedagogical manner and will appeal to scientists, astronomers and graduate students interested in extragalactic astronomy.
Download or read book Space Time and Gravitation written by Arthur Stanley Eddington and published by Read Books Ltd. This book was released on 2013-05-31 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text provides an account of various experiments, that demonstrate a simplified reality where space and time are relegated to their proper source – the observer. The principles of these experiments and theories originate from the ideas of Einstein, and this text aims to present this 'new' outlook without the need for extensive knowledge of mathematics, physics, or philosophy. This text will be of considerable use to those with a keen interest in physics, and would make for a great addition to any bookshelf. The chapters of this book include: 'The Fitzgerald Contraction', 'Relativity', 'The World of Four Dimensions', 'Fields of Force', 'Kinds of Space', 'The New Law of Gravitation and the Old Law', 'Weighing Light', 'Other Tests of The Theory', 'Momentum and Energy', etcetera. We are publishing this antiquarian book now in an affordable, modern edition - complete with a new biography of the author.
Download or read book Cosmological Physics written by J. A. Peacock and published by Cambridge University Press. This book was released on 1999 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive and authoritative introduction to contemporary cosmology for advanced undergraduate and graduate students.
Download or read book Quarks Leptons and The Big Bang Second Edition written by Jonathan Allday and published by CRC Press. This book was released on 2001-01-01 with total page 1336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quarks, Leptons and The Big Bang is a clear, readable and self-contained introduction to particle physics and related areas of cosmology. It bridges the gap between non-technical popular accounts and textbooks for advanced students. The book concentrates on presenting the subject from the modern perspective of quarks, leptons and the forces between them. This book will be of interest to students, teachers and general science readers interested in fundamental ideas of modern physics.
Download or read book Progress in Fine Particle Plasmas written by Tetsu Mieno and published by BoD – Books on Demand. This book was released on 2020-08-26 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the field of plasma physics, plasmas (including charged fine particles) have been actively studied for more than 40 years, and special features of wave phenomena, self-organizations of the particles, potential formations, fluid-like motions of the particles, generations of fine particles in the plasmas, etc. have been investigated. Here, these plasmas are called “fine particle plasmas”, which are also called “dusty plasmas” and “complex plasmas”. This book intends to provide the reader with the recent progress of studies of fine particle plasmas from the viewpoints of wide and interdisciplinary directions, such as self-organized fine particles, Coulomb crystal formation, behaviors of fine particles, their stability, and syntheses of nano-sized particles in reactive plasmas. Further, the phenomena of dense grain particles and the effects of massive neutrinos in galaxy clustering are included.
