Download or read book Constraining Neutrino Masses with Gravitational Lensing of the Cosmic Microwave Background written by Gabrielle Simard and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "By deflecting photon trajectories, weak gravitational lensing shifts cosmic microwave background (CMB) anisotropies. The power spectrum of the lensing deflection field carries significant information about structure formation.The growth of structure in the universe is affected by neutrinos, confirmed to have a non-zero total mass by the latest neutrino flavor oscillation experiments. Using statistical estimators of the deflection field, we have evaluated through a Fisher forecast the capacity of present and near future CMB experiments SPT-SZ, SPTpol and Planck to constrain cosmological parameters and the total neutrino mass. We find that including lensing information in the forecast allows the SPT-SZ, SPTpol and Planck combined constraint to improve from 0.32 eV to 0.089 eV. The 1-sigma constraint on the sum of neutrino masses from Planck alone improves from 0.39 eV to 0.11 eV when including lensing. Furthermore, we conclude that a greater SPTpol survey area is favored in order to maximize the SPT-SZ, SPTpol and Planck combined constraint on the total neutrino mass. " --
Download or read book Probing Gravity and the Neutrinos with Cosmology written by S. A. Thomas and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is related to the growth of structure in the late-time Universe. It addresses both the measurement of this structure and the use of such information in constraining fundamental underlying physics. This includes the gravitational framework and the sum of the three neutrinos'mass. The thesis starts by using weak gravitational lensing data (CFHTLS) to constrain a modification of gravity that is invoked to provide the observed accelerated expansion in the Universe. This is shown to disfavour the model in question. It is, however, incapable of placing any bounds on the growth parameter that represents extensions to gravity. The future of weak lensing in probing general relativity is illustrated with forecasts on the growth signature and power spectrum parameter using the proposed Euclid probe. A measurement is made on the clustering of Luminous Red Galaxies (LRGs) in the Universe. This represents a new photometric galaxy clustering angular power spectrum: MegaZ LRG Data Release 7 (DR7). The cosmological constraints are demonstrated to be competitive with spectroscopic surveys and complementary to the WMAP5 data. Specifically, bounds of f_b \equiv \Omega _b / \Omega _m = 0.173 \pm 0.046 and \Omega_m = 0.260 \pm 0.035 are placed. Potential systematics in the data are discussed and examined. The work concludes by placing one of the most stringent constraints available of the sum of the three neutrino masses. By combining cosmic microwave background information, distance measures from supernovae and baryon acoustic oscillations with growth from the MegaZ LRG galaxy clustering data, produced earlier, the limit is found to be \sum m_v
Download or read book Detecting Gravitational Lensing from the Cosmic Microwave Background written by Chang Feng and published by . This book was released on 2014 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gravitational lensing of the Cosmic Microwave Background (CMB) measures all the matter content in the Universe. It can be used to constrain neutrino masses, calibrate biased tracers for large scale structure, and remove contamination of primordial B-modes. The theoretical framework, which includes simulations and reconstruction of gravitational lensing effects from CMB observations, has been established and applied through this dissertation. From observations of the CMB's temperature anisotropy, WMAP datasets are used to probe gravitational lensing effects. It is found that the lensing signal can not be directly detected from WMAP alone but can be indirectly detected at >3[sigma] if WMAP's CMB observations are cross-correlated with galaxy surveys. Other than the CMB temperature, the CMB polarization is of great importance because the CMB's polarization is more sensitive than its temperature to probing lensing effects. From the ground-based small-scale polarization experiment, POLARBEAR, we (for the first time) measure polarization lensing and lensing B-modes from different types of correlation functions. The B-mode power spectrum is measured, showing the evidence for lensing B-modes at the 2[sigma] level. Lensing reconstruction with B-modes is also performed. From the auto-correlation of the lensing reconstruction with B-modes, the polarization lensing and lensing B-mode signal is measured at the 4.2[sigma] level, including systematics. This signal measures dark matter fluctuations with 27% uncertainty. The matter structure seen in the lensing reconstruction is further validated by the cross-correlation with cosmic infrared background, which shows evidence for polarization lensing at 4[sigma]. This state-of-the-art technique is capable of mapping all gravitating matter in the Universe, is sensitive to the sum of neutrino masses, and is essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.
Download or read book Constraining Cosmological Parameters with Gravitational Lensing of the Cosmic Microwave Background written by Gabrielle Simard and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The cosmic microwave background (CMB) anisotropies are a direct probe of early Universe physics. They also carry information about the late Universe through different secondary effects, including gravitational lensing. Propagating away from the last scattering surface, the primary CMB photons are deflected by the intervening large-scale structure, creating slight distortions in the CMB radiation temperature and polarization patterns that can be detected statistically. In this thesis, we present constraints on the parameters describing our Universe on cosmological scales obtained with the use of CMB gravitational lensing measurements. We begin with a description of the current cosmological model and follow with a review of gravitational lensing effects on the CMB observables.We then present bounds on cosmological parameters set by the lensing power spectrum estimated from a combined SPT+Planck CMB temperature map on the SPT-SZ 2500 square-degrees patch of sky.Adding lensing information to primary CMB data helps tightening constraints on cosmological parameters affecting late-time growth, such as the matter fluctuation amplitude today, the spatial curvature and the sum of neutrino masses.Measurements of the CMB polarization sourced in the early Universe are hindered by the additional polarization created by the gravitational lensing deflections; this contaminating lensing signal can be estimated and removed. We discuss projected constraints on the scale-dependence of the primordial CMB polarization signal assuming that the lensing induced contamination can be subtracted through different scenarios." --
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 A Measurement of the Cosmic Microwave Background Gravitational Lensing Potential and Its Power Spectrum from 500 Deg2 of SPTpol Data written by Laura Monica Mocanu and published by . This book was released on 2017 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Neutrino Mass written by Guido Altarelli and published by Springer. This book was released on 2004-02-24 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reviews the current state of knowledge of neutrino masses and the related question of neutrino oscillations. After an overview of the theory of neutrino masses and mixings, detailed accounts are given of the laboratory limits on neutrino masses, astrophysical and cosmological constraints on those masses, experimental results on neutrino oscillations, the theoretical interpretation of those results, and theoretical models of neutrino masses and mixings. The book concludes with an examination of the potential of long-baseline experiments. This is an essential reference text for workers in elementary-particle physics, nuclear physics, and astrophysics.
Download or read book Illuminating the Background written by Nathan James Miller and published by . This book was released on 2012 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cosmic microwave background provides a wealth of information about the origin and history of the universe. The statistics of the anisotropy and the polarization of the cosmic microwave background, among other things, can tell us about the distribution of matter, the redshift of reionization, and the nature of the primordial fluctuations. From the lensing of cosmic microwave background due to intervening matter, we can extract information about neutrinos and the equation of state of dark energy. A measurement of the large angular scale B-mode polarization has been called the "smoking gun'' of inflation, a theory that describes a possible early rapid expansion of the universe. The focus of current experiments is to measure this B-mode polarization, while several experiments, such as POLARBEAR, are also looking to measure the lensing of the cosmic microwave background. This dissertation will discuss several different topics in cosmic microwave background polarization research. I will make predictions for future experiments and I will also show analysis for two current experiments, POLARBEAR and BICEP. I will show how beam systematics affect the measurement of cosmological parameters and how well we must limit these systematics in order to get unbiased constraints on cosmological parameters for future experiments. I will discuss a novel way of using the temperature-polarization cross-correlation to constrain the amount of inflationary gravitational waves. Through Markov Chain Monte Carlo methods, I will determine how well future experiments will be able to constrain the neutrino masses and their degeneracy parameters. I will show results from current data analysis and calibration being done on the Cedar Flat deployment for the POLARBEAR experiment which is currently being constructed in the Atacama desert in Chile. Finally, I will analyze the claim of detection of cosmological birefringence in the BICEP data and show that there is reason to believe it is due to systematic effects in the data.
Download or read book A Course in Cosmology written by Dragan Huterer and published by Cambridge University Press. This book was released on 2023-02-28 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: This new graduate textbook adopts a pedagogical approach to contemporary cosmology that enables readers to build an intuitive understanding of theory and data, and of how they interact, which is where the greatest advances in the field are currently being made. Using analogies, intuitive explanations of complex topics, worked examples and computational problems, the book begins with the physics of the early universe, and goes on to cover key concepts such as inflation, dark matter and dark energy, large‐scale structure, and cosmic microwave background. Computational and data analysis techniques, and statistics, are integrated throughout the text, particularly in the chapters on late-universe cosmology, while another chapter is entirely devoted to the basics of statistical methods. A solutions manual for end-of-chapter problems is available to instructors, and suggested syllabi, based on different course lengths and emphasis, can be found in the Preface. Online computer code and datasets enhance the student learning experience.
Download or read book New Constraints on Neutrino Masses from Cosmology written by and published by . This book was released on 2006 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysics And Cosmology Proceedings Of The 26th Solvay Conference On Physics written by Roger D Blandford and published by World Scientific. This book was released on 2016-03-23 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ever since 1911, the Solvay Conferences have shaped modern physics. The format is quite different from other conferences as the emphasis is placed on discussion. The 26th edition held in October 2014 in Brussels and chaired by Roger Blandford continued this tradition and addressed some of the most pressing open questions in the fields of astrophysics and cosmology, gathering many of the leading figures working on a wide variety of profound problems.The proceedings contain the 'rapporteur talks' giving a broad overview with unique insights by distinguished renowned scientists. These lectures cover the five sessions: 'Neutron Stars', 'Black Holes', 'Cosmic Dawn', 'Dark Matter' and 'Cosmic Microwave Background'.In the Solvay tradition, the proceedings also include the prepared comments to the rapporteur talks. The discussions among the participants — expert, yet lively and sometimes contentious — have been edited to retain to retain their flavor and are reproduced in full. The reader is taken on a breathtaking ride through 42 years of extraordinary discovery since astrophysics was last on the Solvay program and 57 years since cosmology was last discussed.
Download or read book Eleventh Marcel Grossmann Meeting The On Recent Developments In Theoretical And Experimental General Relativity Gravitation And Relativistic Field Theories In 3 Volumes Proceedings Of The Mg11 Meeting On General Relativity written by Hagen Kleinert and published by World Scientific. This book was released on 2008-09-04 with total page 3129 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Marcel Grossmann Meetings are three-yearly forums that meet to discuss recent advances in gravitation, general relativity and relativistic field theories, emphasizing their mathematical foundations, physical predictions and experimental tests. These meetings aim to facilitate the exchange of ideas among scientists, to deepen our understanding of space-time structures, and to review the status of ongoing experiments and observations testing Einstein's theory of gravitation either from ground or space-based experiments. Since the first meeting in 1975 in Trieste, Italy, which was established by Remo Ruffini and Abdus Salam, the range of topics presented at these meetings has gradually widened to accommodate issues of major scientific interest, and attendance has grown to attract more than 900 participants from over 80 countries.This proceedings volume of the eleventh meeting in the series, held in Berlin in 2006, highlights and records the developments and applications of Einstein's theory in diverse areas ranging from fundamental field theories to particle physics, astrophysics and cosmology, made possible by unprecedented technological developments in experimental and observational techniques from space, ground and underground observatories. It provides a broad sampling of the current work in the field, especially relativistic astrophysics, including many reviews by leading figures in the research community.
Download or read book Cosmological Probes of Light Relics written by Benjamin Wallisch and published by Springer Nature. This book was released on 2019-11-20 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: The wealth of recent cosmic microwave background and large-scale structure data has transformed the field of cosmology. These observations have not only become precise enough to answer questions about the universe on the largest scales, but also to address puzzles in the microscopic description of Nature. This thesis investigates new ways of probing the early universe, the properties of neutrinos and the possible existence of other light particles. In particular, based on detailed theoretical insights and novel analyses, new evidence for the cosmic neutrino background is found in the distribution of galaxies and in cosmic microwave background data. This tests the Standard Model of particle physics and the universe back to a time when it was about one second old. Furthermore, it is demonstrated that future observations will be capable of probing physics beyond the Standard Model since they can achieve a particular target which would either allow the detection of any light particles that have ever been in thermal equilibrium or imply strong bounds on their properties.
Download or read book The Physics Associated with Neutrino Masses written by Diego Aristizabal Sierra and published by Frontiers Media SA. This book was released on 2020-01-13 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
Download or read book Weigh Them All written by Sunny Vagnozzi and published by Springer. This book was released on 2021-08-15 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: The three neutrinos are ghostly elementary particles that exist all across the Universe. Though every second billions of them fly through us, they are extremely hard to detect. We used to think they had no mass, but recently discovered that in fact they have a tiny mass. The quest for the neutrino mass scale and mass ordering (specifying how the three masses are distributed) is an extremely exciting one, and will open the door towards new physics operating at energy scales we can only ever dream of reaching on Earth. This thesis explores the use of measurements of the Cosmic Microwave Background (the oldest light reaching us, a snapshot of the infant Universe) and maps of millions of galaxies to go after the neutrino mass scale and mass ordering. Neutrinos might teach us something about the mysterious dark energy powering the accelerated expansion of the Universe, or about cosmic inflation, which seeded the initial conditions for the Universe. Though extremely baffling, neutrinos are also an exceptionally exciting area of research, and cosmological observations promise to reveal a great deal about these elusive particles in the coming years.
Download or read book Probing Dark Energy with Theory and Observations written by Roland De Putter and published by . This book was released on 2010 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: The discovery of cosmic acceleration twelve years ago implies that our universe is dominated by dark energy, which is either a tiny cosmological constant or a mysterious fluid with large negative pressure, or that Einstein's successful theory of gravity needs to be modified at large scales/low energies. Since then, independent evidence of a number of cosmological probes has firmly established the picture of a universe where dark energy (or the effective contribution from a modification of gravity) makes up about $72 \%$ of the total energy density. Whichever of the options mentioned above will turn out to be the right one, a satisfying explanation for cosmic acceleration will likely lead to important new insights in fundamental physics. The question of the physics behind cosmic acceleration is thus one of the most intriguing open questions in modern physics. In this thesis, we calculate current constraints on dark energy and study how to optimally use the cosmological tools at our disposal to learn about its nature. We will first present constraints from a host of recent data on the dark energy sound speed and equation of state for different dark energy models including early dark energy. We then study the observational properties of purely kinetic k-essence models and show how they can in principle be straightforwardly distinguished from quintessence models by their equation of state behavior. We next consider a large, representative set of dark energy and modified gravity models and show that they can be divided into a small set of observationally distinct classes. We also find that all non-early dark energy models we consider can be modeled extremely well by a simple linear equation of state form. We will then go on to discuss a number of alternative, model independent parametrizations of dark energy properties. Among other things, we find that principal component analysis is not as model-independent as one would like it to be and that assuming a fixed value for the high redshift equation of state can lead to a dangerous bias in the determination of the equation of state at low redshift. Finally, we discuss using weak gravitational lensing of cosmic microwave background (CMB) anisotropies as a cosmological probe. We compare different methods for extracting cosmological information from the lensed CMB and show that CMB lensing will in the future be a useful tool for constraining dark energy and neutrino mass. Whereas marginalizing over neutrino mass can degrade dark energy constraints, CMB lensing helps to break the degeneracy between the two and restores the dark energy constraints to the level of the fixed neutrino mass case.
Download or read book Gravitational Lensing the Cosmic Microwave Background and Cluster Masses written by and published by . This book was released on 2007 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
