Download or read book The Intrinsic Bispectrum of the Cosmic Microwave Background written by Guido Walter Pettinari and published by Springer. This book was released on 2015-08-27 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nominated as an outstanding thesis by Professor Robert Crittenden of the Institute of Cosmology and Gravitation in Portsmouth, and winner of the Michael Penston Prize for 2014 given by the Royal Astronomical Society for the best doctoral thesis in Astronomy or Astrophysics, this work aims to shed light on one of the most important probes of the early Universe: the bispectrum of the cosmic microwave background. The CMB bispectrum is a potential window on exciting new physics, as it is sensitive to the non-Gaussian features in the primordial fluctuations, the same fluctuations that evolved into today’s planets, stars and galaxies. However, this invaluable information is potentially screened, as not all of the observed non-Gaussianity is of primordial origin. Indeed, a bispectrum arises even for perfectly Gaussian initial conditions due to non-linear dynamics, such as CMB photons scattering off free electrons and propagating in an inhomogeneous Universe. Dr. Pettinari introduces the reader to this intrinsic bispectrum in a pedagogic way, building up from the standard model of cosmology and from cosmological perturbation theory, the tool cosmologists use to unravel the history of the cosmos. In doing so, he introduces SONG, a new and efficient code for solving the second-order Einstein and Boltzmann equations. Next, he moves on to answer the crucial question: is the intrinsic bispectrum going to screen the primordial signal in the CMB? Using SONG, he computes the intrinsic bispectrum and shows how its contamination leads to a small bias in the estimates of primordial non-Gaussianity, a great news for the prospect of using CMB data to probe primordial non-Gaussianity.
Download or read book The Cosmic Microwave Background written by Júlio C. Fabris and published by Springer. This book was released on 2016-10-07 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series of texts composing this book is based on the lectures presented during the II José Plínio Baptista School of Cosmology, held in Pedra Azul (Espírito Santo, Brazil) between 9 and 14 March 2014. This II JBPCosmo has been entirely devoted to the problem of understanding theoretical and observational aspects of Cosmic Background Radiation (CMB).The CMB is one of the most important phenomena in Physics and a fundamental probe of our Universe when it was only 400,000 years old. It is an extraordinary laboratory where we can learn from particle physics to cosmology; its discovery in 1965 has been a landmark event in the history of physics.The observations of the anisotropy of the cosmic microwave background radiation through the satellites COBE, WMAP and Planck provided a huge amount of data which are being analyzed in order to discover important informations regarding the composition of our universe and the process of structure formation.
Download or read book Non Gaussianity and Extragalactic Foregrounds to the Cosmic Microwave Background written by Fabien Lacasa and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis, written in english, studies the non-Gaussianity (NG) of extragalactic foregrounds to the Cosmic Microwave Background (CMB), the latter being one of the golden observables of today's cosmology. In the last decade has emerged research for deviations of the CMB to the Gaussian law, as they would discriminate the models for the generation of primordial perturbations. However the CMB measurements, e.g. by the Planck satellite, are contaminated by several foregrounds. I studied in particular the extragalactic foregrounds which trace the large scale structure of the universe : radio and infrared point-sources and the thermal Sunyaev-Zel'dovich effect (tSZ). I hence describe the statistical tools to characterise a random field : the correlation functions, and their harmonic counterpart : the polyspectra. In particular the bispectrum is the lowest order indicator of NG, with the highest potential signal to noise ratio (SNR). I describe how it can be estimated on data, accounting for a potential mask (e.g. galactic), and propose a method to visualise the bispectrum, which is more adapted than the already existing ones. I then describe the covariance of a polyspectrum measurement, a method to generate non-Gaussian simulations, and how the statistic of a 3D field projects onto the sphere when integrating along the line-of-sight. I then describe the generation of density perturbations by the standard inflation model and their possible NG, how they yield the CMB anisotropies and grow to form the large scale structure of today's universe. To describe this large scale structure, I present the halo model and propose a diagrammatic method to compute the polyspectra of the galaxy density field and to have a simple and powerful representation of the involved terms. I then describe the foregrounds to the CMB, galactic as well as extragalactic. I briefly describe the physics of the thermal Sunyaev-Zel'dovich effect and how to describe its spatial distribution with the halo model. I then describe the extragalactic point-sources and present a prescription for the NG of clustered sources. For the Cosmic Infrared Background (CIB) I introduce a physical modeling with the halo model and the diagrammatic method. I compute numerically the 3D galaxy bispectrum and produce the first theoretical prediction of the CIB angular bispectrum. I show the contributions of the different terms and the temporal evolution of the galaxy bispectrum. For the CIB angular bispectrum, I show its different terms, its scale and configuration dependence, and how it varies with model parameters. By Fisher analysis, I show it allows very good constraints on these parameters, complementary to or better than those coming from the power spectrum. Finally, I describe my work on measuring NG. I first introduce an estimator for the amplitude of the CIB bispectrum, and show how to combine it with similar ones for radio sources and the CMB, for a joint constraint of the different sources of NG. I quantify the contamination of extragalactic point-sources to the estimation of primordial NG ; for Planck it is negligible for the central CMB frequencies. I then describe my measurement of the CIB bispectrum on Planck data ; it is very significantly detected at 217, 353 and 545 GHz with SNR ranging from 5.8 to 28.7. Its shape is consistent between frequencies, as well as the intrinsic amplitude of NG. Ultimately, I describe my measurement of the tSZ bispectrum, on simulations and on Compton parameter maps estimated by Planck, validating the robustness of the estimation thanks to realist foreground simulations. The tSZ bispectrum is very significantly detected with SNR~200. Its amplitude and its scale and configuration dependence are consistent with the projected map of detected clusters and tSZ simulations. Finally, this measurement allows to put a constraint on the cosmological parameters : sigma_8*(Omega_b/0.049)^0.35 = 0.74+/-0.04 in agreement with other tSZ statistics.
Download or read book Tetrad Formalism for Exact Cosmological Observables written by Ermis Mitsou and published by Springer Nature. This book was released on 2020-06-25 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a novel mathematical formalism, based on the tetrad formulation of differential geometry, for describing cosmological observables exactly and conveniently. It covers all the standard observables, i.e. distances, weak lensing, number counts and cosmic microwave background, and also includes a detailed derivation of general-relativistic matrix kinetic theory. All the fully nonlinear equations are derived in detail and the mathematical content is self-contained, so that readers require only a basic knowledge of general relativity. Moreover, the authors discuss several subtle issues that are usually overlooked in the literature and, in particular, issues that distinguish this formalism from the more approximative standard practice.
Download or read book Current Topics in Astrofundamental Physics The Cosmic Microwave Background written by Norma Sanchez and published by Springer Science & Business Media. This book was released on 2001-03-31 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Study Institute, Erice, Ettore Majorana Centre, Italy, 5-16 December 1999
Download or read book The Vector Mode in the Second order Cosmological Perturbation Theory written by Shohei Saga and published by Springer. This book was released on 2018-01-11 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis sheds valuable new light on the second-order cosmological perturbation theory, extensively discussing it in the context of cosmic microwave background (CMB) fluctuations. It explores the observational consequences of the second-order vector mode, and addresses magnetic field generation and the weak lensing signatures, which are key phenomena of the vector mode. The author demonstrates that the second-order vector mode, which never appears at the linear-order level, naturally arises from the non-linear coupling of the first-order scalar modes. This leads to the remarkable statement that the vector-order mode clearly contributes to the generation of cosmological magnetic fields. Moreover, the weak lensing observations are shown to be accessible to the vector mode. On the basis of ongoing and forthcoming observations, the thesis concludes that the second-order vector mode is detectable.
Download or read book The Cosmic Microwave Background written by Ruth Durrer and published by Cambridge University Press. This book was released on 2020-12-17 with total page 519 pages. Available in PDF, EPUB and Kindle. Book excerpt: This graduate textbook describes the physics of the Cosmic Microwave Background, arguably the most important topic in modern cosmology.
Download or read book Searches for the Supersymmetric Partner of the Top Quark Dark Matter and Dark Energy at the ATLAS Experiment written by Nicolas Maximilian Köhler and published by Springer Nature. This book was released on 2019-09-13 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astrophysical observations implying the existence of Dark Matter and Dark Energy, which are not described by the Standard Model (SM) of particle physics, have led to extensions of the SM predicting new particles that could be directly produced at the Large Hadron Collider (LHC) at CERN. Based on 2015 and 2016 ATLAS proton-proton collision data, this thesis presents searches for the supersymmetric partner of the top quark, for Dark Matter, and for DarkEnergy, in signatures with jets and missing transverse energy. Muon detection is key to some of the most important LHC physics results, including the discovery of the Higgs boson and the measurement of its properties. The efficiency with which muons can be detected with the ATLAS detector is measured using Z boson decays. The performance of high-precision Monitored Drift Tube muon chambers under background rates similar to the ones expected for the High Luminosity-LHC is studied.
Download or read book The Cosmic Microwave Background written by Slobodan Perovic and published by Cambridge University Press. This book was released on 2024-06-30 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explanations of the cosmic microwave background prompt this unique case study of theory building in modern science.
Download or read book The Tao of Cosmos written by Zhen G. Ma and published by Simon and Schuster. This book was released on 2024-07-23 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: • Connects the philosophy of the I Ching with key recent advances in cosmology, such as the Big Bang theory, Roger Penrose's cyclic conformal cosmology, and his and Stuart Hameroff's cosmic quantum brain dynamics • Explains the Taoist cosmology of Heaven-Humanity Oneness in the context of Teilhard de Chardin’s evolutionism, Thomas Berry’s cosmogenetic trinity, and Brian Swimme’s 12 cosmological powers • Examines the holographic unity of Heaven, Earth, and Humankind at microcosmic, mesocosmic, and macrocosmic scales Is the universe inert and empty, or is it in some way responsive to consciousness? Breathing new life into a question that has perplexed philosophers since ancient times and scientists for the last century, physicist Zhen G. Ma, Ph.D., offers a quantitative “theory of everything” that beautifully integrates ancient I Ching philosophy, Eastern Taoism, modern cosmology, and the quantum brain dynamics of consciousness. Sharing insights from his years of research on space physics and black-hole spacetime—complemented by studies in quantum brain dynamics and cosmological powers with Brian Swimme at the California Institute of Integral Studies—Ma explains how his integrated theory draws primarily on two key paradigms in the philosophy of cosmology and consciousness: Swimme’s cosmic creation story of the universe as a green dragon and Roger Penrose and Stuart Hameroff’s cosmic consciousness. Extending these theories further, Ma shows how they harmonize not only with the ancient Eastern philosophy of the oneness of heaven and humanity, but also with a holographic cosmic principle that connects the quantum-plasma brain with the universe and earth with heaven. He then looks at this holographic unity in the cyclic process of birth, growth, decay, and death and shows how it resonates with Einstein-Friedmann’s cosmological dynamics and Hawking-Penrose’s quantum gravity model. Demonstrating a quantitative paradigm of everything, Ma shows how humanity is inextricably and holistically blended into the cosmic fabric of the universe.
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 The Cosmic Microwave Background written by C.H. Lineweaver and published by Springer. This book was released on 1997-10-31 with total page 0 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 Data Analysis in Cosmology written by Vicent J. Martinez and published by Springer Science & Business Media. This book was released on 2009-03-15 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: The amount of cosmological data has dramatically increased in the past decades due to an unprecedented development of telescopes, detectors and satellites. Efficiently handling and analysing new data of the order of terabytes per day requires not only computer power to be processed but also the development of sophisticated algorithms and pipelines. Aiming at students and researchers the lecture notes in this volume explain in pedagogical manner the best techniques used to extract information from cosmological data, as well as reliable methods that should help us improve our view of the universe.
Download or read book Cosmic Microwave Background and Large Scale Structure of the Universe written by Yong-Ik Byun and published by . This book was released on 1998 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Cosmic Microwave Background written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 3K The Cosmic Microwave Background Radiation written by R. B. Partridge and published by Cambridge University Press. This book was released on 1995-07-13 with total page 397 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review covering all aspects of the study of the cosmic background radiation remnant of the hot Big Bang origin of the Universe.
Download or read book Data Analysis in Cosmology written by Vicent J. Martinez and published by Springer. This book was released on 2009-07-09 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: The amount of cosmological data has dramatically increased in the past decades due to an unprecedented development of telescopes, detectors and satellites. Efficiently handling and analysing new data of the order of terabytes per day requires not only computer power to be processed but also the development of sophisticated algorithms and pipelines. Aiming at students and researchers the lecture notes in this volume explain in pedagogical manner the best techniques used to extract information from cosmological data, as well as reliable methods that should help us improve our view of the universe.
