Cosmological Simulations For Precision Dark Energy Measurements With Wide Field Galaxy Surveys
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Synthetic Source Injection In The Dark Energy Survey
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Author : Megan M. Tabbutt
language : en
Publisher:
Release Date : 2023
Synthetic Source Injection In The Dark Energy Survey written by Megan M. Tabbutt and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2023 with categories.
Presented here is the Dark Energy Survey's (DES) Synthetic Source Injection (SSI) methodology and applications to precision cosmology for our Year 6 analysis of large-scale structure. Our methodology is predicated on injecting models of real objects obtained from our very high signal-to-noise Deep Field observations into our single-epoch wide field images which are then processed identically to the original wide images. Inherent to this methodology, is that the synthetic sources automatically inherit the same systematics of the real wide field data, a highly sought after achievement for many systematics modeling pipelines that is nearly impossible to achieve from forward modeling techniques alone. In the end, we obtain wide field photometry catalogs of the deep field objects including their inheritance of the systematics. These catalogs are a Monte Carlo sampling of the transfer function of the survey. They can be used for calibration and diagnostics, as well as aid in the calculation and validation of our key project analysis and consequentially our measurement of cosmological parameter constraints through the photometric redshift calibration of the weak lensing sources and the magnification bias estimate for the lens galaxy samples. Both of which are critical to the measurements of the three 2-point correlation functions: cosmic shear, galaxy clustering and galaxy-galaxy lensing, from which we constrain cosmological parameters. This methodology was introduced for our year 3 analysis, and was the first example of using SSI to directly calibrate the cosmological measurements from a wide field survey. The refinement and expansion of the methodology is presented here. Specifically, we improved our mirroring of the wide field image processing pipeline to now fully recreate it. We refactored our code-base to be able to run our SSI at multiple super-computing centers, minimizing wall time and maximizing allocations. We also developed a new injection scheme that injects sources which are preferentially more useful to the cosmological analyses. These as well as other updates, our initial year 6 SSI results, and their applications to precision cosmology will be discussed at length in this thesis.
Precision Cosmology With Galaxy Cluster Surveys
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Author : Hao-Yi Wu
language : en
Publisher: Stanford University
Release Date : 2011
Precision Cosmology With Galaxy Cluster Surveys written by Hao-Yi Wu and has been published by Stanford University this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011 with categories.
The acceleration of the universe, which is often attributed to "dark energy, " has posed one of the main challenges to fundamental physics. Galaxy clusters provide one of the most sensitive probes of dark energy because their abundance reflects the growth rate of large-scale structure and the expansion rate of the universe. Several large galaxy cluster surveys will soon provide tremendous statistical power to constrain the properties of dark energy; however, the constraining power of these surveys will be determined by how well systematic errors are controlled. Of these systematic errors, the dominant one comes from inferring cluster masses using observable signals of clusters, the so-called "observable--mass distribution." This thesis focuses on extracting dark energy information from forthcoming large galaxy cluster surveys, including how we maximize the cosmological information, how we control important systematics, and how precisely we need to calibrate theoretical models. We study how multi-wavelength follow-up observations can improve cluster mass calibration in optical surveys. We also investigate the impact of theoretical uncertainties in calibrating the spatial distributions of galaxy clusters on dark energy constraints. In addition, we explore how the formation history of galaxy clusters impacts the self-calibration of cluster mass. In addition, we use N-body simulations to develop a new statistical sample of cluster-size halos in order to further understand the observable--mass distribution. We study the completeness of subhalos in our cluster sample by comparing them with the satellite galaxies in the Sloan Digital Sky Survey. We also study how subhalo selections impact the inferred correlation between formation time and optical mass tracers, including cluster richness and velocity dispersion.
Simulations Of Dark Energy Cosmologies
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Author : Elise Jennings
language : en
Publisher: Springer Science & Business Media
Release Date : 2012-05-27
Simulations Of Dark Energy Cosmologies written by Elise Jennings and has been published by Springer Science & Business Media this book supported file pdf, txt, epub, kindle and other format this book has been release on 2012-05-27 with Science categories.
A major outstanding problem in physics is understanding the nature of the dark energy that is driving the accelerating expansion of the Universe. This thesis makes a significant contribution by demonstrating, for the first time, using state-of-the-art computer simulations, that the interpretation of future galaxy survey measurements is far more subtle than is widely assumed, and that a major revision to our models of these effects is urgently needed. The work contained in the thesis was used by the WiggleZ dark energy survey to measure the growth rate of cosmic structure in 2011 and had a direct impact on the design of the surveys to be conducted by the European Space Agency's Euclid mission, a 650 million euro project to measure dark energy.
Probing Cosmic Dark Matter And Dark Energy With Weak Gravitational Lensing Statistics
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Author : Masato Shirasaki
language : en
Publisher: Springer
Release Date : 2015-11-18
Probing Cosmic Dark Matter And Dark Energy With Weak Gravitational Lensing Statistics written by Masato Shirasaki and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015-11-18 with Science categories.
In this book the applicability and the utility of two statistical approaches for understanding dark energy and dark matter with gravitational lensing measurement are introduced. For cosmological constraints on the nature of dark energy, morphological statistics called Minkowski functionals (MFs) to extract the non-Gaussian information of gravitational lensing are studied. Measuring lensing MFs from the Canada–France–Hawaii Telescope Lensing survey (CFHTLenS), the author clearly shows that MFs can be powerful statistics beyond the conventional approach with the two-point correlation function. Combined with the two-point correlation function, MFs can constrain the equation of state of dark energy with a precision level of approximately 3–4 % in upcoming surveys with sky coverage of 20,000 square degrees. On the topic of dark matter, the author studied the cross-correlation of gravitational lensing and the extragalactic gamma-ray background (EGB). Dark matter annihilation is among the potential contributors to the EGB. The cross-correlation is a powerful probe of signatures of dark matter annihilation, because both cosmic shear and gamma-ray emission originate directly from the same dark matter distribution in the universe. The first measurement of the cross-correlation using a real data set obtained from CFHTLenS and the Fermi Large Area Telescope was performed. Comparing the result with theoretical predictions, an independent constraint was placed on dark matter annihilation. Future lensing surveys will be useful to constrain on the canonical value of annihilation cross section for a wide range of mass of dark matter annihilation. Future lensing surveys will be useful to constrain on the canonical value of annihilation cross section for a wide range of mass of dark matter.
Dark Energy Survey The The Story Of A Cosmological Experiment
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Author : Ofer Lahav
language : en
Publisher: World Scientific
Release Date : 2020-08-19
Dark Energy Survey The The Story Of A Cosmological Experiment written by Ofer Lahav and has been published by World Scientific this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020-08-19 with Science categories.
'The past cultures of astronomy and physics evolved their own distinct personalities. The book describes an important milestone in the history of the unification of the two fields and provides an excellent summary of the methods used to explore one of the greatest mysteries in physics today: dark energy.'Physics TodayThis book is about the Dark Energy Survey, a cosmological experiment designed to investigate the physical nature of dark energy by measuring its effect on the expansion history of the universe and on the growth of large-scale structure. The survey saw first light in 2012, after a decade of planning, and completed observations in 2019. The collaboration designed and built a 570-megapixel camera and installed it on the four-metre Blanco telescope at the Cerro Tololo Inter-American Observatory in the Chilean Andes. The survey data yielded a three-dimensional map of over 300 million galaxies and a catalogue of thousands of supernovae. Analysis of the early data has confirmed remarkably accurately the model of cold dark matter and a cosmological constant. The survey has also offered new insights into galaxies, supernovae, stellar evolution, solar system objects and the nature of gravitational wave events.A project of this scale required the long-term commitment of hundreds of scientists from institutions all over the world. The chapters in the first three sections of the book were either written by these scientists or based on interviews with them. These chapters explain, for a non-specialist reader, the science analysis involved. They also describe how the project was conceived, and chronicle some of the many and diverse challenges involved in advancing our understanding of the universe. The final section is trans-disciplinary, including inputs from a philosopher, an anthropologist, visual artists and a poet. Scientific collaborations are human endeavours and the book aims to convey a sense of the wider context within which science comes about.This book is addressed to scientists, decision makers, social scientists and engineers, as well as to anyone with an interest in contemporary cosmology and astrophysics.Related Link(s)
High Performance Computing In Science And Engineering 17
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Author : Wolfgang E. Nagel
language : en
Publisher: Springer
Release Date : 2018-02-16
High Performance Computing In Science And Engineering 17 written by Wolfgang E. Nagel and has been published by Springer this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-02-16 with Computers categories.
This book presents the state-of-the-art in supercomputer simulation. It includes the latest findings from leading researchers using systems from the High Performance Computing Center Stuttgart (HLRS) in 2017. The reports cover all fields of computational science and engineering ranging from CFD to computational physics and from chemistry to computer science with a special emphasis on industrially relevant applications. Presenting findings of one of Europe’s leading systems, this volume covers a wide variety of applications that deliver a high level of sustained performance.The book covers the main methods in high-performance computing. Its outstanding results in achieving the best performance for production codes are of particular interest for both scientists and engineers. The book comes with a wealth of color illustrations and tables of results.
New Worlds New Horizons In Astronomy And Astrophysics
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Author : National Research Council
language : en
Publisher: National Academies Press
Release Date : 2011-02-04
New Worlds New Horizons In Astronomy And Astrophysics written by National Research Council and has been published by National Academies Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2011-02-04 with Science categories.
Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's. Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity. New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.
The Astronomy Revolution
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Author : Donald G. York
language : en
Publisher: Taylor & Francis
Release Date : 2016-04-19
The Astronomy Revolution written by Donald G. York and has been published by Taylor & Francis this book supported file pdf, txt, epub, kindle and other format this book has been release on 2016-04-19 with Science categories.
Some 400 years after the first known patent application for a telescope by Hans Lipperhey, The Astronomy Revolution: 400 Years of Exploring the Cosmos surveys the effects of this instrument and explores the questions that have arisen out of scientific research in astronomy and cosmology. Inspired by the international New Vision 400 conference held
Astrophysical Masers Iau S336
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Author : International Astronomical Union. Symposium
language : en
Publisher: Cambridge University Press
Release Date : 2018-09-13
Astrophysical Masers Iau S336 written by International Astronomical Union. Symposium and has been published by Cambridge University Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-09-13 with Science categories.
Summarizes state of the art observations and theories pertaining to astrophysical masers and their environments, for graduate students and researchers.
Cosmological Clues
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Author : Carolyn Devereux
language : en
Publisher: CRC Press
Release Date : 2020-12-23
Cosmological Clues written by Carolyn Devereux and has been published by CRC Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020-12-23 with Science categories.
Did the Universe have a beginning? Will it have an end? Or has it always been the same, never changing? This is the subject of cosmology; the study of the Universe, and this book provides a perfect introduction to the subject for anyone that is interested in the wonders of our Universe This book provides an accessible overview of the Standard Model of Cosmology, which is explained in six Cosmological Clues, including evidence for the Big Bang and dark matter and dark energy - the keystones of modern cosmology. It takes readers through some of the most exciting questions in cosmology, such as what evidence do we have that the Universe started from the Big Bang? Has dark matter been observed? Will we ever know what dark energy is? Are the multiverses real? And could the Universe be a hologram? This book is an ideal guide for anyone interested in finding out more about our Universe. It will be of interest to those studying cosmology for the first time, including readers without a scientific background, who have an interest in looking up at the stars and wondering where they all came from! Key features: Contains the latest evidence for the Big Bang, dark matter, and dark energy and explores exciting scientific ideas, such as inflation and multiverses Provides a clear explanation of the main theories of how the Universe evolved based on key observations - the Cosmological Clues Gives the reader a concise introduction to the scientific process, using cosmology as the example, and explores why it has been so successful in creating the technologies we have today