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States with Regards to Finding If the Cosmological Constant Is, Or Is Not a ‘Vacuum’ Field Andrew Beckwith, [email protected]
Consequences of squeezing initially coherent (semi classical) states with regards to finding if the cosmological constant is, or is not a ‘vacuum’ field Andrew Beckwith, [email protected], Abstract The following document is to prepare an analysis on if the cosmological constant is a vacuum field. Candidates for how to analyze this issue come up in terms of brane theory, modified treatments of WdM theory (pseudo time component added) and/ or how to look at squeezing of vacuum states, as initially coherent semi classical constructions, or string theory versions of coherent states. The article presents a thought experiment if there is a non zero graviton mass, and at the end, in the conclusion states experimental modeling criteria which may indicate if a non zero graviton mass is measurable, which would indicate the existence, de facto of a possible replacement for DE, based upon non zero mass gravitons, and indications for a replacement for a cosmological constant. Introduction: Dr. Karim1 mailed the author with the following question which will be put in quotes: The challenge of resolving the following question: At the Big Bang the only form of energy released is in the form of geometry – gravity. intense gravity field lifts vacuum fields to positive energies, So an electromagnetic vacuum of density 10122 kg/m3 should collapse under its own gravity. But this does not happen - that is one reason why the cosmological constant cannot be the vacuum field. Why? Answering this question delves into what the initial state of the universe should be, in terms of either vacuum energy, or something else. -
General Relativity and Cosmology: Unsolved Questions and Future Directions
Article General Relativity and Cosmology: Unsolved Questions and Future Directions Ivan Debono 1,∗,† and George F. Smoot 1,2,3,† 1 Paris Centre for Cosmological Physics, APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/lrfu, Observatoire de Paris, Sorbonne Paris Cité, 10, rue Alice Domon et Léonie Duquet, 75205 Paris CEDEX 13, France; [email protected] 2 Physics Department and Lawrence Berkeley National Laboratory, University of California, Berkeley, 94720 CA, USA 3 Helmut and Anna Pao Sohmen Professor-at-Large, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, 999077 Hong Kong, China * Correspondence: [email protected]; Tel.: +33-1-57276991 † These authors contributed equally to this work. Academic Editors: Lorenzo Iorio and Elias C. Vagenas Received: 21 August 2016; Accepted: 14 September 2016; Published: 28 September 2016 Abstract: For the last 100 years, General Relativity (GR) has taken over the gravitational theory mantle held by Newtonian Gravity for the previous 200 years. This article reviews the status of GR in terms of its self-consistency, completeness, and the evidence provided by observations, which have allowed GR to remain the champion of gravitational theories against several other classes of competing theories. We pay particular attention to the role of GR and gravity in cosmology, one of the areas in which one gravity dominates and new phenomena and effects challenge the orthodoxy. We also review other areas where there are likely conflicts pointing to the need to replace or revise GR to represent correctly observations and consistent theoretical framework. Observations have long been key both to the theoretical liveliness and viability of GR. -
Arxiv:Hep-Th/0209231 V1 26 Sep 2002 Tbs,Daai N Uigi Eurdfrsae Te Hntetemlvcu Olead to Vacuum Thermal the Anisotropy
SLAC-PUB-9533 BRX TH-505 October 2002 SU-ITP-02/02 Initial conditions for inflation Nemanja Kaloper1;2, Matthew Kleban1, Albion Lawrence1;3;4, Stephen Shenker1 and Leonard Susskind1 1Department of Physics, Stanford University, Stanford, CA 94305 2Department of Physics, University of California, Davis, CA 95616 3Brandeis University Physics Department, MS 057, POB 549110, Waltham, MA 02454y 4SLAC Theory Group, MS 81, 2575 Sand Hill Road, Menlo Park, CA 94025 Free scalar fields in de Sitter space have a one-parameter family of states invariant under the de Sitter group, including the standard thermal vacuum. We show that, except for the thermal vacuum, these states are unphysical when gravitational interactions are arXiv:hep-th/0209231 v1 26 Sep 2002 included. We apply these observations to the quantum state of the inflaton, and find that at best, dramatic fine tuning is required for states other than the thermal vacuum to lead to observable features in the CMBR anisotropy. y Present and permanent address. *Work supported in part by Department of Energy Contract DE-AC03-76SF00515. 1. Introduction In inflationary cosmology, cosmic microwave background (CMB) data place a tanta- lizing upper bound on the vacuum energy density during the inflationary epoch: 4 V M 4 1016 GeV : (1:1) ∼ GUT ∼ Here MGUT is the \unification scale" in supersymmetric grand unified models, as predicted by the running of the observed strong, weak and electromagnetic couplings above 1 T eV in the minimal supersymmetric standard model. If this upper bound is close to the truth, the vacuum energy can be measured directly with detectors sensitive to the polarization of the CMBR. -
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Ai miei genitori. ii Indice Introduzione ................................................................................................... 1 1. Cent’anni di Cosmologia ............................................................................ 2 2. Il Modello Cosmologico Standard ΛCDM .................................................. 6 3. Questioni aperte e modelli alternativi (cenni) .......................................... 12 4. Conclusioni .............................................................................................. 14 Bibliografia .................................................................................................. 16 Ringraziamenti ............................................................................................. 18 iii iv “La più sublime, la più nobile tra le Fisiche scienze ella è senza dubbio l’Astronomia. L’uomo s’innalza per mezzo di essa come al di sopra di se medesimo, e giunge a conoscere la causa dei fenomeni più straordinari.” (Giacomo Leopardi 1) Introduzione Il presente lavoro intende offrire un riassunto dello “stato dell’arte” della Cosmologia: dopo averne ripercorso per sommi capi la storia degli ultimi cent’anni (cap.1), verrà illustrato il Modello Cosmologico Standard “ ΛCDM” (cap.2), che è quello generalmente accettato dalla comunità scientifica allo stato attuale delle conoscenze; infine, si farà un breve “excursus” sulle questioni “aperte” e sui modelli cosmologici alternativi (cap.3). La Cosmologia si può definire in maniera sintetica come lo studio dell’Universo -
Rayappa a Kasi Rusch to Riches.Pdf
RUSH TO RICHES The War on Creation Paul Wiegelmann Lectures on Environmental Studies: 2 RUSH TO RICHES The War on Creation Rayappa A. Kasi Dharmaram Publications Bangalore 560 029, India 2011 Rush to Riches: The War on Creation By Rayappa A. Kasi A. Kattupadi Post Vellore 632011, India Website: www.planetschaser.com Email: [email protected]; Phone: 09443537885 Paul Wiegelmann Lectures on Environmental Studies: 2 © Faculty of Philosophy Dharmaram Vidya Kshetram Bangalore 560 029, India Email: [email protected] First Edition, 2011 Published by Dharmaram Publications ISBN: 978-81-89958-45-9 Printed at: National Printing Press, Bangalore Price: INì 395; US$ 40 Dharmaram Publications Dharmaram College, Bangalore 560 029, India Tel. 080/4111 6227; 4111 6137; 4111 6111 E-mail: [email protected] Web: www.dharmarampublications.com In memory of all the species of animals and plants perished in the war on creation Other Publications from the Author 1. Earth: The Lost Paradise of Happiness (2009) 2. Global Warming: Everything You Want to Know! (2009) 3. Biosphere: The Fragility of Our Natural Heritage (2010) 4. Lithosphere: A Destructive Creator (2010) 5. Hydrosphere: The Giver of Life (2010) 6. Atmosphere: A Thin Line between Life and Death (2010) 7. Earth: Designed for Biodiversity (2010) 8. Youth: An Avatar of New Earth (2011) 9. Apes to Angels: Man Reaches his Omega Point (2011) Cover Illustration This picture, the oil-soaked bird from Gulf of Mexico, represents the agony and pain that the Creation is undergoing as a result of human conflict with Nature. It is a loud cry of Creation for help. -
Observational Cosmology - 30H Course 218.163.109.230 Et Al
Observational cosmology - 30h course 218.163.109.230 et al. (2004–2014) PDF generated using the open source mwlib toolkit. See http://code.pediapress.com/ for more information. PDF generated at: Thu, 31 Oct 2013 03:42:03 UTC Contents Articles Observational cosmology 1 Observations: expansion, nucleosynthesis, CMB 5 Redshift 5 Hubble's law 19 Metric expansion of space 29 Big Bang nucleosynthesis 41 Cosmic microwave background 47 Hot big bang model 58 Friedmann equations 58 Friedmann–Lemaître–Robertson–Walker metric 62 Distance measures (cosmology) 68 Observations: up to 10 Gpc/h 71 Observable universe 71 Structure formation 82 Galaxy formation and evolution 88 Quasar 93 Active galactic nucleus 99 Galaxy filament 106 Phenomenological model: LambdaCDM + MOND 111 Lambda-CDM model 111 Inflation (cosmology) 116 Modified Newtonian dynamics 129 Towards a physical model 137 Shape of the universe 137 Inhomogeneous cosmology 143 Back-reaction 144 References Article Sources and Contributors 145 Image Sources, Licenses and Contributors 148 Article Licenses License 150 Observational cosmology 1 Observational cosmology Observational cosmology is the study of the structure, the evolution and the origin of the universe through observation, using instruments such as telescopes and cosmic ray detectors. Early observations The science of physical cosmology as it is practiced today had its subject material defined in the years following the Shapley-Curtis debate when it was determined that the universe had a larger scale than the Milky Way galaxy. This was precipitated by observations that established the size and the dynamics of the cosmos that could be explained by Einstein's General Theory of Relativity. -
Introducing Astrogen: the Astronomy Genealogy Project
Journal of Astronomical History and Heritage, 19(3), 298–304 (2016). INTRODUCING ASTROGEN: THE ASTRONOMY GENEALOGY PROJECT Joseph S. Tenn Sonoma State University, Rohnert Park, CA 94928, USA. Email: [email protected] Abstract: The Astronomy Genealogy Project (―AstroGen‖), a project of the Historical Astronomy Division of the American Astronomical Society (AAS), will soon appear on the AAS website. Ultimately, it will list the world‘s astronomers with their highest degrees, theses for those who wrote them, academic advisors (supervisors), universities, and links to the astronomers or their obituaries, their theses when on-line, and more. At present the AstroGen team is working on those who earned doctorates with astronomy-related theses. We show what can be learned already, with just ten countries essentially completed. Keywords: Academic genealogy, astronomers, Ph.D. theses, dissertations 1 INTRODUCTION ries we have studied (listed in Section 3) went to Arthur Williams Wright (Figure 1), who became AstroGen is coming. The Astronomy Genealogy the first person outside Europe to earn a Ph.D. Project will soon appear on the website of the in science and one of the first three Ph.D.s in American Astronomical Society (AstroGen: any subject in the United States. His thesis, https://astrogen.aas.org/). Under construction Having Given the Velocity and Direction of since early 2013, the project will list the world‘s Motion of a Meteor on Entering the Atmosphere doctoral theses (dissertations) on astronomy- of the Earth, to Determine its Orbit about the related topics, along with information about the Sun, Taking into Account the Attraction of Both theses and their authors. -
Topics in Cosmology: Island Universes, Cosmological Perturbations and Dark Energy
TOPICS IN COSMOLOGY: ISLAND UNIVERSES, COSMOLOGICAL PERTURBATIONS AND DARK ENERGY by SOURISH DUTTA Submitted in partial fulfillment of the requirements for the degree Doctor of Philosophy Department of Physics CASE WESTERN RESERVE UNIVERSITY August 2007 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the dissertation of ______________________________________________________ candidate for the Ph.D. degree *. (signed)_______________________________________________ (chair of the committee) ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ ________________________________________________ (date) _______________________ *We also certify that written approval has been obtained for any proprietary material contained therein. To the people who have believed in me. Contents Dedication iv List of Tables viii List of Figures ix Abstract xiv 1 The Standard Cosmology 1 1.1 Observational Motivations for the Hot Big Bang Model . 1 1.1.1 Homogeneity and Isotropy . 1 1.1.2 Cosmic Expansion . 2 1.1.3 Cosmic Microwave Background . 3 1.2 The Robertson-Walker Metric and Comoving Co-ordinates . 6 1.3 Distance Measures in an FRW Universe . 11 1.3.1 Proper Distance . 12 1.3.2 Luminosity Distance . 14 1.3.3 Angular Diameter Distance . 16 1.4 The Friedmann Equation . 18 1.5 Model Universes . 21 1.5.1 An Empty Universe . 22 1.5.2 Generalized Flat One-Component Models . 22 1.5.3 A Cosmological Constant Dominated Universe . 24 1.5.4 de Sitter space . 26 1.5.5 Flat Matter Dominated Universe . 27 1.5.6 Curved Matter Dominated Universe . 28 1.5.7 Flat Radiation Dominated Universe . 30 1.5.8 Matter Radiation Equality . 32 1.6 Gravitational Lensing . 34 1.7 The Composition of the Universe . -
Harwit M. in Search of the True Universe.. the Tools, Shaping, And
In Search of the True Universe Astrophysicist and scholar Martin Harwit examines how our understanding of the Cosmos advanced rapidly during the twentieth century and identifies the factors contributing to this progress. Astronomy, whose tools were largely imported from physics and engineering, benefited mid-century from the U.S. policy of coupling basic research with practical national priorities. This strategy, initially developed for military and industrial purposes, provided astronomy with powerful tools yielding access – at virtually no cost – to radio, infrared, X-ray, and gamma-ray observations. Today, astronomers are investigating the new frontiers of dark matter and dark energy, critical to understanding the Cosmos but of indeterminate socio-economic promise. Harwit addresses these current challenges in view of competing national priorities and proposes alternative new approaches in search of the true Universe. This is an engaging read for astrophysicists, policy makers, historians, and sociologists of science looking to learn and apply lessons from the past in gaining deeper cosmological insight. MARTIN HARWIT is an astrophysicist at the Center for Radiophysics and Space Research and Professor Emeritus of Astronomy at Cornell University. For many years he also served as Director of the National Air and Space Museum in Washington, D.C. For much of his astrophysical career he built instruments and made pioneering observations in infrared astronomy. His advanced textbook, Astrophysical Concepts, has taught several generations of astronomers through its four editions. Harwit has had an abiding interest in how science advances or is constrained by factors beyond the control of scientists. His book Cosmic Discovery first raised these questions. -
IYPT Reference Kit 2013
Second draft // September 28, 2012 Preparation to the Young Physicists’ Tournaments’ 2013 Ilya Martchenko, 1 * Andrei Klishin, 2 Reza Montazeri Namin, 3 Piotr Podziemski, 4 Stanisłaŭ Piatruša, 5 Łukasz Gładczuk, 6 Stanisław Świdwiński, 7 and Andrei Schetnikov 8 1 University of Fribourg and Lund University; 2 Massachusetts Institute of Technology; 3 Sharif University of Technology; 4 Warsaw University of Technology; 5 Belarusian State University; 6 University of Warsaw; 7 Almukantarat, Warsaw; 8 SIGMA, Novosibirsk Invitation The IYPT is seeking for sponsors The IYPT is ideally suited for a sponsorship portfolio that focuses on supporting youth, education, science, and technology Being a partner of the IYPT offers a unique and powerful publicity The existing partners are excited to speak out on the IYPT in their annual reports, media releases, or bulletins for customers There are meantime many ways you can help as a volunteer fundraiser :-) Advertisement the first IYPT-themed book where all articles underwent rigorous peer review 98 reviews from 25 reviewers 32 papers selected revisions, resubmissions before getting accepted How to tackle the IYPT problems? How to structure a report? Look through the historical solutions in the Archive :-) What level is competitive? How to set the goals, fix the an opportunity for goal-oriented priorities, and set the direction critical learning of the work? examples, not guidelines How were people resolving those solutions were good, but particular issues in the past? yours should be better! -
Timelike BKL Singularities and Chaos in ADS/CFT
Timelike BKL singularities and chaos in ADS/CFT Edgar ShaghoulianB;K and Huajia WangK;L B Department of Physics, UCSB, Santa Barbara, CA 93106 K Stanford Institute of Theoretical Physics, Stanford University L Department of Physics, University of Illinois at Urbana-Champaign Abstract We study the nature of a family of curvature singularities which are precisely the timelike cousins of the spacelike singularities studied by Belinski, Khalatnikov, and Lifshitz (BKL). We show that the approach to the singularity can be modeled by a billiard ball problem on hyperbolic space, just as in the case of BKL. For pure gravity, generic chaotic behavior is retained in (3 + 1) dimensions, and we provide evidence that it disappears in higher dimensions. We speculate that such singularities, if occurring in AdS/CFT and of the chaotic variety, may be interpreted as (transient) chaotic renormalization group flows which exhibit features reminiscent of chaotic duality cascades. arXiv:1601.02599v2 [hep-th] 10 Feb 2016 1 Contents 1 Introduction 1 2 BKL summary 3 3 Timelike BKL singularities4 4 Radial billiards 8 5 Timelike BKL singularities in AdS/CFT 14 6 Discussion 22 A Spacelike BKL summary 23 B Symmetry well artifacts in Bianchi IX 29 1 Introduction It is remarkable that the intellectual environment created by the Cold War could have a positive effect on the practice of science. Distinct approaches to problems were developed instead of singular techniques dominating the field. One of the beautiful pieces of theoretical physics to emerge from the isolated intellectual environment of the former Soviet Union is the analysis by Belinski, Khalatnikov, and Lifshitz (BKL) of the nature of cosmological singularities in general relativity [1,2,3]. -
General Relativity and Cosmology: Unsolved Questions and Future Directions
Article General Relativity and Cosmology: Unsolved Questions and Future Directions Ivan Debono 1,∗,† and George F. Smoot 1,2,3,† 1 Paris Centre for Cosmological Physics, APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/lrfu, Observatoire de Paris, Sorbonne Paris Cité, 10, rue Alice Domon et Léonie Duquet, 75205 Paris CEDEX 13, France 2 Physics Department and Lawrence Berkeley National Laboratory, University of California, Berkeley, 94720 CA, USA; [email protected] 3 Helmut and Anna Pao Sohmen Professor-at-Large, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, 999077 Hong Kong, China * Correspondence: [email protected]; Tel.: +33-1-57276991 † These authors contributed equally to this work. Academic Editors: Lorenzo Iorio and Elias C. Vagenas Received: 21 August 2016; Accepted: 14 September 2016; Published: 28 September 2016 Abstract: For the last 100 years, General Relativity (GR) has taken over the gravitational theory mantle held by Newtonian Gravity for the previous 200 years. This article reviews the status of GR in terms of its self-consistency, completeness, and the evidence provided by observations, which have allowed GR to remain the champion of gravitational theories against several other classes of competing theories. We pay particular attention to the role of GR and gravity in cosmology, one of the areas in which one gravity dominates and new phenomena and effects challenge the orthodoxy. We also review other areas where there are likely conflicts pointing to the need to replace or revise GR to represent correctly observations and consistent theoretical framework. Observations have long been key both to the theoretical liveliness and viability of GR.