Lecture II Polarization Anisotropy Spectrum
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Detection of Polarization in the Cosmic Microwave Background Using DASI
Detection of Polarization in the Cosmic Microwave Background using DASI Thesis by John M. Kovac A Dissertation Submitted to the Faculty of the Division of the Physical Sciences in Candidacy for the Degree of Doctor of Philosophy The University of Chicago Chicago, Illinois 2003 Copyright c 2003 by John M. Kovac ° (Defended August 4, 2003) All rights reserved Acknowledgements Abstract This is a sample acknowledgement section. I would like to take this opportunity to The past several years have seen the emergence of a new standard cosmological model thank everyone who contributed to this thesis. in which small temperature di®erences in the cosmic microwave background (CMB) I would like to take this opportunity to thank everyone. I would like to take on degree angular scales are understood to arise from acoustic oscillations in the hot this opportunity to thank everyone. I would like to take this opportunity to thank plasma of the early universe, sourced by primordial adiabatic density fluctuations. In everyone. the context of this model, recent measurements of the temperature fluctuations have led to profound conclusions about the origin, evolution and composition of the uni- verse. Given knowledge of the temperature angular power spectrum, this theoretical framework yields a prediction for the level of the CMB polarization with essentially no free parameters. A determination of the CMB polarization would therefore provide a critical test of the underlying theoretical framework of this standard model. In this thesis, we report the detection of polarized anisotropy in the Cosmic Mi- crowave Background radiation with the Degree Angular Scale Interferometer (DASI), located at the Amundsen-Scott South Pole research station. -
2.1.5 Stress-Strain Relation for Anisotropic Materials
,/... + -:\ 2.1.5Stress-strain Relation for AnisotropicMaterials The generalizedHook's law relatingthe stressesto strainscan be writtenin the form U2, 13,30-32]: o,=C,,€, (i,i =1,2,.........,6) Where: o, - Stress('ompttnents C,, - Elasticity matrix e,-Straincomponents The material properties (elasticity matrix, Cr) has thirty-six constants,stress-strain relations in the materialcoordinates are: [30] O1 LI CT6 a, l O2 03_ a, -t ....(2-6) T23 1/ )1 T32 1/1l 'Vt) Tt2 C16 c66 I The relations in equation (3-6) are referred to as characterizing anisotropicmaterials since there are no planes of symmetry for the materialproperties. An alternativename for suchanisotropic material is a triclinic material. If there is one plane of material property symmetry,the stress- strainrelations reduce to: -'+1-/ ) o1 c| ct2 ct3 0 0 crc €l o2 c12 c22 c23 0 0 c26 a: ct3 C23 ci3 0 0 c36 o-\ o3 ....(2-7) 723 000cqqc450 y)1 T3l 000c4sc5s0 Y3l T1a ct6 c26 c36 0 0 c66 1/t) Where the plane of symmetryis z:0. Such a material is termed monoclinicwhich containstfirfen independentelastic constants. If there are two brthogonalplanes of material property symmetry for a material,symmetry will existrelative to a third mutuallyorthogonal plane. The stress-strainrelations in coordinatesaligned with principal material directionswhich are parallel to the intersectionsof the three orthogonalplanes of materialsymmetry, are'. Ol ctl ct2ctl000 tl O2 Ct2 c22c23000 a./ o3 ct3 c23c33000 * o-\ ....(2-8) T23 0 00c4400 y)1 yll 731 0 000css0 712 0 0000cr'e 1/1) 'lt"' -' , :t i' ,/ Suchmaterial is calledorthotropic material.,There is no interaction betweennormal StreSSeS ot r 02, 03) andanisotropic materials. -
Introduction to Temperature Anisotropies of Cosmic Microwave Background Radiation
Prog. Theor. Exp. Phys. 2014, 06B101 (13 pages) DOI: 10.1093/ptep/ptu073 CMB Cosmology Introduction to temperature anisotropies of Cosmic Microwave Background radiation Naoshi Sugiyama1,2,3,∗ 1Department of Physics, Nagoya University, Nagoya, 464-8602, Japan 2Kobayashi Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya, Japan 3Kavli IPMU, University of Tokyo, Japan ∗E-mail: [email protected] Received April 7, 2014; Revised April 28, 2014; Accepted April 30, 2014; Published June 11 , 2014 Downloaded from ............................................................................... Since its serendipitous discovery, Cosmic Microwave Background (CMB) radiation has been recognized as the most important probe of Big Bang cosmology. This review focuses on temper- ature anisotropies of CMB which make it possible to establish precision cosmology. Following a brief history of CMB research, the physical processes working on the evolution of CMB http://ptep.oxfordjournals.org/ anisotropies are discussed, including gravitational redshift, acoustic oscillations, and diffusion dumping. Accordingly, dependencies of the angular power spectrum on various cosmological parameters, such as the baryon density, the matter density, space curvature of the universe, and so on, are examined and intuitive explanations of these dependencies are given. ............................................................................... Subject Index E56, E60, E63, E65 by guest on June 19, 2014 1. Introduction: A brief history of research on CMB Since its serendipitous discovery in 1965 by Penzias and Wilson [1], Cosmic Microwave Background (CMB) radiation, which was first predicted by Alpher and Herman in 1948 [2] as radiation at 5 Kat the present time, has become one of the most important observational probes of Big Bang cosmology. CMB is recognized as a fossil of the early universe because it directly brings information from the epoch of recombination, which is 370, 000 years after the beginning of the universe. -
Arxiv:2008.11688V1 [Astro-Ph.CO] 26 Aug 2020
APS/123-QED Cosmology with Rayleigh Scattering of the Cosmic Microwave Background Benjamin Beringue,1 P. Daniel Meerburg,2 Joel Meyers,3 and Nicholas Battaglia4 1DAMTP, Centre for Mathematical Sciences, Wilberforce Road, Cambridge, UK, CB3 0WA 2Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands 3Department of Physics, Southern Methodist University, 3215 Daniel Ave, Dallas, Texas 75275, USA 4Department of Astronomy, Cornell University, Ithaca, New York, USA (Dated: August 27, 2020) The cosmic microwave background (CMB) has been a treasure trove for cosmology. Over the next decade, current and planned CMB experiments are expected to exhaust nearly all primary CMB information. To further constrain cosmological models, there is a great benefit to measuring signals beyond the primary modes. Rayleigh scattering of the CMB is one source of additional cosmological information. It is caused by the additional scattering of CMB photons by neutral species formed during recombination and exhibits a strong and unique frequency scaling ( ν4). We will show that with sufficient sensitivity across frequency channels, the Rayleigh scattering/ signal should not only be detectable but can significantly improve constraining power for cosmological parameters, with limited or no additional modifications to planned experiments. We will provide heuristic explanations for why certain cosmological parameters benefit from measurement of the Rayleigh scattering signal, and confirm these intuitions using the Fisher formalism. In particular, observation of Rayleigh scattering P allows significant improvements on measurements of Neff and mν . PACS numbers: Valid PACS appear here I. INTRODUCTION direction of propagation of the (primary) CMB photons. There are various distinguishable ways that cosmic In the current era of precision cosmology, the Cosmic structures can alter the properties of CMB photons [10]. -
Multidisciplinary Design Project Engineering Dictionary Version 0.0.2
Multidisciplinary Design Project Engineering Dictionary Version 0.0.2 February 15, 2006 . DRAFT Cambridge-MIT Institute Multidisciplinary Design Project This Dictionary/Glossary of Engineering terms has been compiled to compliment the work developed as part of the Multi-disciplinary Design Project (MDP), which is a programme to develop teaching material and kits to aid the running of mechtronics projects in Universities and Schools. The project is being carried out with support from the Cambridge-MIT Institute undergraduate teaching programe. For more information about the project please visit the MDP website at http://www-mdp.eng.cam.ac.uk or contact Dr. Peter Long Prof. Alex Slocum Cambridge University Engineering Department Massachusetts Institute of Technology Trumpington Street, 77 Massachusetts Ave. Cambridge. Cambridge MA 02139-4307 CB2 1PZ. USA e-mail: [email protected] e-mail: [email protected] tel: +44 (0) 1223 332779 tel: +1 617 253 0012 For information about the CMI initiative please see Cambridge-MIT Institute website :- http://www.cambridge-mit.org CMI CMI, University of Cambridge Massachusetts Institute of Technology 10 Miller’s Yard, 77 Massachusetts Ave. Mill Lane, Cambridge MA 02139-4307 Cambridge. CB2 1RQ. USA tel: +44 (0) 1223 327207 tel. +1 617 253 7732 fax: +44 (0) 1223 765891 fax. +1 617 258 8539 . DRAFT 2 CMI-MDP Programme 1 Introduction This dictionary/glossary has not been developed as a definative work but as a useful reference book for engi- neering students to search when looking for the meaning of a word/phrase. It has been compiled from a number of existing glossaries together with a number of local additions. -
Small-Scale Anisotropies of the Cosmic Microwave Background: Experimental and Theoretical Perspectives
Small-Scale Anisotropies of the Cosmic Microwave Background: Experimental and Theoretical Perspectives Eric R. Switzer A DISSERTATION PRESENTED TO THE FACULTY OF PRINCETON UNIVERSITY IN CANDIDACY FOR THE DEGREE OF DOCTOR OF PHILOSOPHY RECOMMENDED FOR ACCEPTANCE BY THE DEPARTMENT OF PHYSICS [Adviser: Lyman Page] November 2008 c Copyright by Eric R. Switzer, 2008. All rights reserved. Abstract In this thesis, we consider both theoretical and experimental aspects of the cosmic microwave background (CMB) anisotropy for ℓ > 500. Part one addresses the process by which the universe first became neutral, its recombination history. The work described here moves closer to achiev- ing the precision needed for upcoming small-scale anisotropy experiments. Part two describes experimental work with the Atacama Cosmology Telescope (ACT), designed to measure these anisotropies, and focuses on its electronics and software, on the site stability, and on calibration and diagnostics. Cosmological recombination occurs when the universe has cooled sufficiently for neutral atomic species to form. The atomic processes in this era determine the evolution of the free electron abundance, which in turn determines the optical depth to Thomson scattering. The Thomson optical depth drops rapidly (cosmologically) as the electrons are captured. The radiation is then decoupled from the matter, and so travels almost unimpeded to us today as the CMB. Studies of the CMB provide a pristine view of this early stage of the universe (at around 300,000 years old), and the statistics of the CMB anisotropy inform a model of the universe which is precise and consistent with cosmological studies of the more recent universe from optical astronomy. -
Cosmic Microwave Background
1 29. Cosmic Microwave Background 29. Cosmic Microwave Background Revised August 2019 by D. Scott (U. of British Columbia) and G.F. Smoot (HKUST; Paris U.; UC Berkeley; LBNL). 29.1 Introduction The energy content in electromagnetic radiation from beyond our Galaxy is dominated by the cosmic microwave background (CMB), discovered in 1965 [1]. The spectrum of the CMB is well described by a blackbody function with T = 2.7255 K. This spectral form is a main supporting pillar of the hot Big Bang model for the Universe. The lack of any observed deviations from a 7 blackbody spectrum constrains physical processes over cosmic history at redshifts z ∼< 10 (see earlier versions of this review). Currently the key CMB observable is the angular variation in temperature (or intensity) corre- lations, and to a growing extent polarization [2–4]. Since the first detection of these anisotropies by the Cosmic Background Explorer (COBE) satellite [5], there has been intense activity to map the sky at increasing levels of sensitivity and angular resolution by ground-based and balloon-borne measurements. These were joined in 2003 by the first results from NASA’s Wilkinson Microwave Anisotropy Probe (WMAP)[6], which were improved upon by analyses of data added every 2 years, culminating in the 9-year results [7]. In 2013 we had the first results [8] from the third generation CMB satellite, ESA’s Planck mission [9,10], which were enhanced by results from the 2015 Planck data release [11, 12], and then the final 2018 Planck data release [13, 14]. Additionally, CMB an- isotropies have been extended to smaller angular scales by ground-based experiments, particularly the Atacama Cosmology Telescope (ACT) [15] and the South Pole Telescope (SPT) [16]. -
Physics of the Cosmic Microwave Background Anisotropy∗
Physics of the cosmic microwave background anisotropy∗ Martin Bucher Laboratoire APC, Universit´eParis 7/CNRS B^atiment Condorcet, Case 7020 75205 Paris Cedex 13, France [email protected] and Astrophysics and Cosmology Research Unit School of Mathematics, Statistics and Computer Science University of KwaZulu-Natal Durban 4041, South Africa January 20, 2015 Abstract Observations of the cosmic microwave background (CMB), especially of its frequency spectrum and its anisotropies, both in temperature and in polarization, have played a key role in the development of modern cosmology and our understanding of the very early universe. We review the underlying physics of the CMB and how the primordial temperature and polarization anisotropies were imprinted. Possibilities for distinguish- ing competing cosmological models are emphasized. The current status of CMB ex- periments and experimental techniques with an emphasis toward future observations, particularly in polarization, is reviewed. The physics of foreground emissions, especially of polarized dust, is discussed in detail, since this area is likely to become crucial for measurements of the B modes of the CMB polarization at ever greater sensitivity. arXiv:1501.04288v1 [astro-ph.CO] 18 Jan 2015 1This article is to be published also in the book \One Hundred Years of General Relativity: From Genesis and Empirical Foundations to Gravitational Waves, Cosmology and Quantum Gravity," edited by Wei-Tou Ni (World Scientific, Singapore, 2015) as well as in Int. J. Mod. Phys. D (in press). -
Glossary of Materials Engineering Terminology
Glossary of Materials Engineering Terminology Adapted from: Callister, W. D.; Rethwisch, D. G. Materials Science and Engineering: An Introduction, 8th ed.; John Wiley & Sons, Inc.: Hoboken, NJ, 2010. McCrum, N. G.; Buckley, C. P.; Bucknall, C. B. Principles of Polymer Engineering, 2nd ed.; Oxford University Press: New York, NY, 1997. Brittle fracture: fracture that occurs by rapid crack formation and propagation through the material, without any appreciable deformation prior to failure. Crazing: a common response of plastics to an applied load, typically involving the formation of an opaque banded region within transparent plastic; at the microscale, the craze region is a collection of nanoscale, stress-induced voids and load-bearing fibrils within the material’s structure; craze regions commonly occur at or near a propagating crack in the material. Ductile fracture: a mode of material failure that is accompanied by extensive permanent deformation of the material. Ductility: a measure of a material’s ability to undergo appreciable permanent deformation before fracture; ductile materials (including many metals and plastics) typically display a greater amount of strain or total elongation before fracture compared to non-ductile materials (such as most ceramics). Elastic modulus: a measure of a material’s stiffness; quantified as a ratio of stress to strain prior to the yield point and reported in units of Pascals (Pa); for a material deformed in tension, this is referred to as a Young’s modulus. Engineering strain: the change in gauge length of a specimen in the direction of the applied load divided by its original gauge length; strain is typically unit-less and frequently reported as a percentage. -
Baryon Acoustic Oscillations Under the Hood
Baryon acoustic oscillations! under the hood Martin White UC Berkeley/LBNL Santa Fe, NM July 2010 Acoustic oscillations seen! First “compression”, at kcstls=π. Density maxm, velocity null. Velocity maximum First “rarefaction” peak at kcstls=2π Acoustic scale is set by the sound horizon at last scattering: s = cstls CMB calibration • Not coincidentally the sound horizon is extremely well determined by the structure of the acoustic peaks in the CMB. WMAP 5th yr data Dominated by uncertainty in ρm from poor constraints near 3rd peak in CMB spectrum. (Planck will nail this!) Baryon oscillations in P(k) • Since the baryons contribute ~15% of the total matter density, the total gravitational potential is affected by the acoustic oscillations with scale set by s. • This leads to small oscillations in the matter power spectrum P(k). – No longer order unity, like in the CMB – Now suppressed by Ωb/Ωm ~ 0.1 • Note: all of the matter sees the acoustic oscillations, not just the baryons. Baryon (acoustic) oscillations RMS fluctuation Wavenumber Divide out the gross trend … A damped, almost harmonic sequence of “wiggles” in the power spectrum of the mass perturbations of amplitude O(10%). Higher order effects • The matter and radiation oscillations are not in phase, and the phase shift depends on k. • There is a subtle shift in the oscillations with k due to the fact that the universe is expanding and becoming more matter dominated. • The finite duration of decoupling and rapid change in mfp means the damping of the oscillations on small scales is not a simple Gaussian shape. -
Are Limits on Cosmic Rotation from Analyses of the Cosmic Microwave Background Credible? Michael J
Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 19 November 2020 doi:10.20944/preprints202011.0520.v1 Article Are limits on cosmic rotation from analyses of the cosmic microwave background credible? Michael J. Longo Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA; email: [email protected] Abstract: Recent analyses of cosmic microwave background (CMB) maps have been interpreted as demonstrating that the Universe was born without an initial rotation. However, these analyses are based on unrealistic models and do not contain essential ingredients such as quantum effects, the strong, weak and gravitational interactions between the components, their intrinsic spins and magnetic moments, as well as primordial black holes. If the Universe was born spinning these effects would distribute the initial spin angular momentum among its components long before the CMB forms at recombination. A primordial spin would now appear as a nonzero total angular momentum of its components along the direction of the original spin, and a primordial large-scale rotation would no longer be apparent. The existence of a special axis or direction would break a fundamental symmetry assumed in general relativity, cosmic isotropy, and a net angular momentum implies a cosmic parity violation. Keywords: Cosmic anisotropy; cosmic microwave background; cosmic rotation; Big Bang spin; parity violation; cosmic axis 1. Introduction An important question in cosmology is the possibility that the Universe was born with a primordial spin angular momentum (PSAM). This would strongly affect its evolution during inflation as it expanded from the initial singularity to its present state. A primordial spin could also help explain some outstanding problems in cosmology as discussed below. -
Advanced Measurements of Silicon Carbide Ceramic Matrix Composites
INL/EXT-12-27032 Advanced Measurements of Silicon Carbide Ceramic Matrix Composites David Hurley Farhad Fazbod Zilong Hua Stephen Reese Marat Khafizov August 2012 The INL is a U.S. Department of Energy National Laboratory operated by Battelle Energy Alliance DISCLAIMER This information was prepared as an account of work sponsored by an agency of the U.S. Government. Neither the U.S. Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness, of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. References herein to any specific commercial product, process, or service by trade name, trade mark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S. Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the U.S. Government or any agency thereof. INL/EXT-12-27032 Advanced Measurements of Silicon Carbide Ceramic Matrix Composites David Hurley Farhad Farzbod Zilong Hua Stephen Reese Marat Khafizov August, 2012 Idaho National Laboratory Materials Science and Engineering Department Idaho Falls, Idaho 83415 http://www.inl.gov Prepared for the U.S. Department of Energy Office of Nuclear Energy Under DOE Idaho Operations Office Contract DE-AC07-05ID14517 ii iii ABSTRACT Silicon carbide (SiC) is being considered as a fuel cladding material for accident tolerant fuel under the Light Water Reactor Sustainability (LWRS) Program sponsored by the Nuclear Energy Division of the Department of Energy.