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Topic 3 Evidence for the Big Bang
Topic 3 Primordial nucleosynthesis Evidence for the Big Bang ! Back in the 1920s it was generally thought that the Universe was infinite ! However a number of experimental observations started to question this, namely: • Red shift and Hubble’s Law • Olber’s Paradox • Radio sources • Existence of CMBR Red shift and Hubble’s Law ! We have already discussed red shift in the context of spectral lines (Topic 2) ! Crucially Hubble discovered that the recessional velocity (and hence red shift) of galaxies increases linearly with their distance from us according to the famous Hubble Law V = H0d where H0 = 69.3 ±0.8 (km/s)/Mpc and 1/H0 = Age of Universe Olbers’ paradox ! Steady state Universe is: infinite, isotropic or uniform (sky looks the same in all directions), homogeneous (our location in the Universe isn’t special) and is not expanding ! Therefore an observer choosing to look in any direction should eventually see a star ! This would lead to a night sky that is uniformly bright (as a star’s surface) ! This is not the case and so the assumption that the Universe is infinite must be flawed Radio sources ! Based on observations of radio sources of different strengths (so-called 2C and 3C surveys) ! The number of radio sources versus source strength concludes that the Universe has evolved from a denser place in the past ! This again appears to rule out the so-called Steady State Universe and gives support for the Big Bang Theory Cosmic Microwave Background ! CMBR was predicted as early as 1949 by Alpher and Herman (Gamow group) as a “remnant -
Report from the Dark Energy Task Force (DETF)
Fermi National Accelerator Laboratory Fermilab Particle Astrophysics Center P.O.Box 500 - MS209 Batavia, Il l i noi s • 60510 June 6, 2006 Dr. Garth Illingworth Chair, Astronomy and Astrophysics Advisory Committee Dr. Mel Shochet Chair, High Energy Physics Advisory Panel Dear Garth, Dear Mel, I am pleased to transmit to you the report of the Dark Energy Task Force. The report is a comprehensive study of the dark energy issue, perhaps the most compelling of all outstanding problems in physical science. In the Report, we outline the crucial need for a vigorous program to explore dark energy as fully as possible since it challenges our understanding of fundamental physical laws and the nature of the cosmos. We recommend that program elements include 1. Prompt critical evaluation of the benefits, costs, and risks of proposed long-term projects. 2. Commitment to a program combining observational techniques from one or more of these projects that will lead to a dramatic improvement in our understanding of dark energy. (A quantitative measure for that improvement is presented in the report.) 3. Immediately expanded support for long-term projects judged to be the most promising components of the long-term program. 4. Expanded support for ancillary measurements required for the long-term program and for projects that will improve our understanding and reduction of the dominant systematic measurement errors. 5. An immediate start for nearer term projects designed to advance our knowledge of dark energy and to develop the observational and analytical techniques that will be needed for the long-term program. Sincerely yours, on behalf of the Dark Energy Task Force, Edward Kolb Director, Particle Astrophysics Center Fermi National Accelerator Laboratory Professor of Astronomy and Astrophysics The University of Chicago REPORT OF THE DARK ENERGY TASK FORCE Dark energy appears to be the dominant component of the physical Universe, yet there is no persuasive theoretical explanation for its existence or magnitude. -
Physical Cosmology," Organized by a Committee Chaired by David N
Proc. Natl. Acad. Sci. USA Vol. 90, p. 4765, June 1993 Colloquium Paper This paper serves as an introduction to the following papers, which were presented at a colloquium entitled "Physical Cosmology," organized by a committee chaired by David N. Schramm, held March 27 and 28, 1992, at the National Academy of Sciences, Irvine, CA. Physical cosmology DAVID N. SCHRAMM Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 The Colloquium on Physical Cosmology was attended by 180 much notoriety. The recent report by COBE of a small cosmologists and science writers representing a wide range of primordial anisotropy has certainly brought wide recognition scientific disciplines. The purpose of the colloquium was to to the nature of the problems. The interrelationship of address the timely questions that have been raised in recent structure formation scenarios with the established parts of years on the interdisciplinary topic of physical cosmology by the cosmological framework, as well as the plethora of new bringing together experts of the various scientific subfields observations and experiments, has made it timely for a that deal with cosmology. high-level international scientific colloquium on the subject. Cosmology has entered a "golden age" in which there is a The papers presented in this issue give a wonderful mul- tifaceted view of the current state of modem physical cos- close interplay between theory and observation-experimen- mology. Although the actual COBE anisotropy announce- tation. Pioneering early contributions by Hubble are not ment was made after the meeting reported here, the following negated but are amplified by this current, unprecedented high papers were updated to include the new COBE data. -
Fine-Tuning, Complexity, and Life in the Multiverse*
Fine-Tuning, Complexity, and Life in the Multiverse* Mario Livio Dept. of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154, USA E-mail: [email protected] and Martin J. Rees Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA, UK E-mail: [email protected] Abstract The physical processes that determine the properties of our everyday world, and of the wider cosmos, are determined by some key numbers: the ‘constants’ of micro-physics and the parameters that describe the expanding universe in which we have emerged. We identify various steps in the emergence of stars, planets and life that are dependent on these fundamental numbers, and explore how these steps might have been changed — or completely prevented — if the numbers were different. We then outline some cosmological models where physical reality is vastly more extensive than the ‘universe’ that astronomers observe (perhaps even involving many ‘big bangs’) — which could perhaps encompass domains governed by different physics. Although the concept of a multiverse is still speculative, we argue that attempts to determine whether it exists constitute a genuinely scientific endeavor. If we indeed inhabit a multiverse, then we may have to accept that there can be no explanation other than anthropic reasoning for some features our world. _______________________ *Chapter for the book Consolidation of Fine Tuning 1 Introduction At their fundamental level, phenomena in our universe can be described by certain laws—the so-called “laws of nature” — and by the values of some three dozen parameters (e.g., [1]). Those parameters specify such physical quantities as the coupling constants of the weak and strong interactions in the Standard Model of particle physics, and the dark energy density, the baryon mass per photon, and the spatial curvature in cosmology. -
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A&A 561, L12 (2014) Astronomy DOI: 10.1051/0004-6361/201323020 & c ESO 2014 Astrophysics Letter to the Editor Possible structure in the GRB sky distribution at redshift two István Horváth1, Jon Hakkila2, and Zsolt Bagoly1,3 1 National University of Public Service, 1093 Budapest, Hungary e-mail: [email protected] 2 College of Charleston, Charleston, SC, USA 3 Eötvös University, 1056 Budapest, Hungary Received 9 November 2013 / Accepted 24 December 2013 ABSTRACT Context. Research over the past three decades has revolutionized cosmology while supporting the standard cosmological model. However, the cosmological principle of Universal homogeneity and isotropy has always been in question, since structures as large as the survey size have always been found each time the survey size has increased. Until 2013, the largest known structure in our Universe was the Sloan Great Wall, which is more than 400 Mpc long located approximately one billion light years away. Aims. Gamma-ray bursts (GRBs) are the most energetic explosions in the Universe. As they are associated with the stellar endpoints of massive stars and are found in and near distant galaxies, they are viable indicators of the dense part of the Universe containing normal matter. The spatial distribution of GRBs can thus help expose the large scale structure of the Universe. Methods. As of July 2012, 283 GRB redshifts have been measured. Subdividing this sample into nine radial parts, each contain- ing 31 GRBs, indicates that the GRB sample having 1.6 < z < 2.1differs significantly from the others in that 14 of the 31 GRBs are concentrated in roughly 1/8 of the sky. -
Time-Dependent Cosmological Interpretation of Quantum Mechanics Emmanuel Moulay
Time-dependent cosmological interpretation of quantum mechanics Emmanuel Moulay To cite this version: Emmanuel Moulay. Time-dependent cosmological interpretation of quantum mechanics. 2016. hal- 01169099v2 HAL Id: hal-01169099 https://hal.archives-ouvertes.fr/hal-01169099v2 Preprint submitted on 18 Nov 2016 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Time-dependent cosmological interpretation of quantum mechanics Emmanuel Moulay∗ Abstract The aim of this article is to define a time-dependent cosmological inter- pretation of quantum mechanics in the context of an infinite open FLRW universe. A time-dependent quantum state is defined for observers in sim- ilar observable universes by using the particle horizon. Then, we prove that the wave function collapse of this quantum state is avoided. 1 Introduction A new interpretation of quantum mechanics, called the cosmological interpre- tation of quantum mechanics, has been developed in order to take into account the new paradigm of eternal inflation [1, 2, 3]. Eternal inflation can lead to a collection of infinite open Friedmann-Lemaˆıtre-Robertson-Walker (FLRW) bub- ble universes belonging to a multiverse [4, 5, 6]. This inflationary scenario is called open inflation [7, 8]. -
Primordial Gravitational Waves and Cosmology Arxiv:1004.2504V1
Primordial Gravitational Waves and Cosmology Lawrence Krauss,1∗ Scott Dodelson,2;3;4 Stephan Meyer 3;4;5;6 1School of Earth and Space Exploration and Department of Physics, Arizona State University, PO Box 871404, Tempe, AZ 85287 2Center for Particle Astrophysics, Fermi National Laboratory PO Box 500, Batavia, IL 60510 3Department of Astronomy and Astrophysics 4Kavli Institute of Cosmological Physics 5Department of Physics 6Enrico Fermi Institute University of Chicago, 5640 S. Ellis Ave, Chicago, IL 60637 ∗To whom correspondence should be addressed; E-mail: [email protected]. The observation of primordial gravitational waves could provide a new and unique window on the earliest moments in the history of the universe, and on possible new physics at energies many orders of magnitude beyond those acces- sible at particle accelerators. Such waves might be detectable soon in current or planned satellite experiments that will probe for characteristic imprints in arXiv:1004.2504v1 [astro-ph.CO] 14 Apr 2010 the polarization of the cosmic microwave background (CMB), or later with di- rect space-based interferometers. A positive detection could provide definitive evidence for Inflation in the early universe, and would constrain new physics from the Grand Unification scale to the Planck scale. 1 Introduction Observations made over the past decade have led to a standard model of cosmology: a flat universe dominated by unknown forms of dark energy and dark matter. However, while all available cosmological data are consistent with this model, the origin of neither the dark energy nor the dark matter is known. The resolution of these mysteries may require us to probe back to the earliest moments of the big bang expansion, but before a period of about 380,000 years, the universe was both hot and opaque to electromagnetic radiation. -
Cosmology Slides
Inhomogeneous cosmologies George Ellis, University of Cape Town 27th Texas Symposium on Relativistic Astrophyiscs Dallas, Texas Thursday 12th December 9h00-9h45 • The universe is inhomogeneous on all scales except the largest • This conclusion has often been resisted by theorists who have said it could not be so (e.g. walls and large scale motions) • Most of the universe is almost empty space, punctuated by very small very high density objects (e.g. solar system) • Very non-linear: / = 1030 in this room. Models in cosmology • Static: Einstein (1917), de Sitter (1917) • Spatially homogeneous and isotropic, evolving: - Friedmann (1922), Lemaitre (1927), Robertson-Walker, Tolman, Guth • Spatially homogeneous anisotropic (Bianchi/ Kantowski-Sachs) models: - Gödel, Schücking, Thorne, Misner, Collins and Hawking,Wainwright, … • Perturbed FLRW: Lifschitz, Hawking, Sachs and Wolfe, Peebles, Bardeen, Ellis and Bruni: structure formation (linear), CMB anisotropies, lensing Spherically symmetric inhomogeneous: • LTB: Lemaître, Tolman, Bondi, Silk, Krasinski, Celerier , Bolejko,…, • Szekeres (no symmetries): Sussman, Hellaby, Ishak, … • Swiss cheese: Einstein and Strauss, Schücking, Kantowski, Dyer,… • Lindquist and Wheeler: Perreira, Clifton, … • Black holes: Schwarzschild, Kerr The key observational point is that we can only observe on the past light cone (Hoyle, Schücking, Sachs) See the diagrams of our past light cone by Mark Whittle (Virginia) 5 Expand the spatial distances to see the causal structure: light cones at ±45o. Observable Geo Data Start of universe Particle Horizon (Rindler) Spacelike singularity (Penrose). 6 The cosmological principle The CP is the foundational assumption that the Universe obeys a cosmological law: It is necessarily spatially homogeneous and isotropic (Milne 1935, Bondi 1960) Thus a priori: geometry is Robertson-Walker Weaker form: the Copernican Principle: We do not live in a special place (Weinberg 1973). -
A Study of John Leslie's Infinite Minds, a Philosophical Cosmology
Document généré le 1 oct. 2021 09:18 Laval théologique et philosophique Infinite Minds, Determinism & Evil A Study of John Leslie’s Infinite Minds, A Philosophical Cosmology Leslie Armour La question de Dieu Volume 58, numéro 3, octobre 2002 URI : https://id.erudit.org/iderudit/000634ar DOI : https://doi.org/10.7202/000634ar Aller au sommaire du numéro Éditeur(s) Faculté de philosophie, Université Laval Faculté de théologie et de sciences religieuses, Université Laval ISSN 0023-9054 (imprimé) 1703-8804 (numérique) Découvrir la revue Citer cette note Armour, L. (2002). Infinite Minds, Determinism & Evil: A Study of John Leslie’s Infinite Minds, A Philosophical Cosmology. Laval théologique et philosophique, 58(3), 597–603. https://doi.org/10.7202/000634ar Tous droits réservés © Laval théologique et philosophique, Université Laval, Ce document est protégé par la loi sur le droit d’auteur. L’utilisation des 2002 services d’Érudit (y compris la reproduction) est assujettie à sa politique d’utilisation que vous pouvez consulter en ligne. https://apropos.erudit.org/fr/usagers/politique-dutilisation/ Cet article est diffusé et préservé par Érudit. Érudit est un consortium interuniversitaire sans but lucratif composé de l’Université de Montréal, l’Université Laval et l’Université du Québec à Montréal. Il a pour mission la promotion et la valorisation de la recherche. https://www.erudit.org/fr/ Laval théologique et philosophique, 58, 3 (octobre 2002) : 597-603 ◆ note critique INFINITE MINDS, DETERMINISM & EVIL A STUDY OF JOHN LESLIE’S INFINITE MINDS, A PHILOSOPHICAL COSMOLOGY * Leslie Armour The Dominican College of Philosophy and Theology Ottawa ohn Leslie’s Infinite Minds is a refreshingly daring book. -
Science and Religion in the Face of the Environmental Crisis
Roger S. Gottlieb, ed., The Oxford Handbook of Religion and Ecology. New York and Oxford: Oxford University Press, 2006. Pages 376-397. CHAPTER 17 .................................................................................................. SCIENCE AND RELIGION IN THE FACE OF THE ENVIRONMENTAL CRISIS ..................................................................................................... HOLMES ROLSTON III BOTH science and religion are challenged by the environmental crisis, both to reevaluate the natural world and to reevaluate their dialogue with each other. Both are thrown into researching fundamental theory and practice in the face of an upheaval unprecedented in human history, indeed in planetary history. Life on Earth is in jeopardy owing to the behavior of one species, the only species that is either scientific or religious, the only species claiming privilege as the "wise spe- cies," Homo sapiens. Nature and the human relation to nature must be evaluated within cultures, classically by their religions, currently also by the sciences so eminent in Western culture. Ample numbers of theologians and ethicists have become persuaded that religion needs to pay more attention to ecology, and many ecologists recognize religious dimensions to caring for nature and to addressing the ecological crisis. Somewhat ironically, just when humans, with their increasing industry and technology, seemed further and further from nature, having more knowledge about natural processes and more power to manage them, just when humans were more and more rebuilding their environments, thinking perhaps to escape nature, the natural world has emerged as a focus of concern. Nature remains the milieu of 376 SCIENCE AND RELIGION 377 culture—so both science and religion have discovered. In a currently popular vocabulary, humans need to get themselves "naturalized." Using another meta- phor, nature is the "womb" of culture, but a womb that humans never entirely leave. -
Quantifying the Sensitivity of Big Bang Nucleosynthesis to Isospin Breaking
W&M ScholarWorks Undergraduate Honors Theses Theses, Dissertations, & Master Projects 5-2016 Quantifying the Sensitivity of Big Bang Nucleosynthesis to Isospin Breaking Matthew Ramin Hamedani Heffernan College of William and Mary Follow this and additional works at: https://scholarworks.wm.edu/honorstheses Part of the Nuclear Commons Recommended Citation Heffernan, Matthew Ramin Hamedani, "Quantifying the Sensitivity of Big Bang Nucleosynthesis to Isospin Breaking" (2016). Undergraduate Honors Theses. Paper 974. https://scholarworks.wm.edu/honorstheses/974 This Honors Thesis is brought to you for free and open access by the Theses, Dissertations, & Master Projects at W&M ScholarWorks. It has been accepted for inclusion in Undergraduate Honors Theses by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. Quantifying the Sensitivity of Big Bang Nucleosynthesis to Isospin Breaking Matthew Heffernan Advisor: Andr´eWalker-Loud Abstract We perform a quantitative study of the sensitivity of Big Bang Nucleosynthesis (BBN) to the two sources of isospin breaking in the Standard Model (SM), the split- 1 ting between the down and up quark masses, δq (md mu) and the electromagnetic ≡ 2 − coupling constant, αf:s:. To very good approximation, the neutron-proton mass split- ting, ∆m mn mp, depends linearly upon these two quantities. In turn, BBN is very ≡ − sensitive to ∆m. A simultaneous study of both of these sources of isospin violation had not yet been performed. Quantifying the simultaneous sensitivity of BBN to δq and αf:s: is interesting as ∆m increases with increasing δq but decreases with increasing αf:s:. A combined analysis may reveal weaker constraints upon possible variations of these fundamental constants of the SM. -
String Theory and Pre-Big Bang Cosmology
IL NUOVO CIMENTO 38 C (2015) 160 DOI 10.1393/ncc/i2015-15160-8 Colloquia: VILASIFEST String theory and pre-big bang cosmology M. Gasperini(1)andG. Veneziano(2) (1) Dipartimento di Fisica, Universit`a di Bari - Via G. Amendola 173, 70126 Bari, Italy and INFN, Sezione di Bari - Bari, Italy (2) CERN, Theory Unit, Physics Department - CH-1211 Geneva 23, Switzerland and Coll`ege de France - 11 Place M. Berthelot, 75005 Paris, France received 11 January 2016 Summary. — In string theory, the traditional picture of a Universe that emerges from the inflation of a very small and highly curved space-time patch is a possibility, not a necessity: quite different initial conditions are possible, and not necessarily unlikely. In particular, the duality symmetries of string theory suggest scenarios in which the Universe starts inflating from an initial state characterized by very small curvature and interactions. Such a state, being gravitationally unstable, will evolve towards higher curvature and coupling, until string-size effects and loop corrections make the Universe “bounce” into a standard, decreasing-curvature regime. In such a context, the hot big bang of conventional cosmology is replaced by a “hot big bounce” in which the bouncing and heating mechanisms originate from the quan- tum production of particles in the high-curvature, large-coupling pre-bounce phase. Here we briefly summarize the main features of this inflationary scenario, proposed a quarter century ago. In its simplest version (where it represents an alternative and not a complement to standard slow-roll inflation) it can produce a viable spectrum of density perturbations, together with a tensor component characterized by a “blue” spectral index with a peak in the GHz frequency range.