DOCSLIB.ORG

New CMB Constraints on the Cosmic Matter Budget

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
New CMB Constraints on the Cosmic Matter Budget View metadata, Newcitation and CMB similar constraintspapers at core.ac.uk on the cosmic matter budget: trouble for nucleosynthesis?brought to you by CORE provided by CERN Document Server Max Tegmark Dept. of Physics, Univ. of Pennsylvania, Philadelphia, PA 19104; [email protected] Matias Zaldarriaga Institute for Advanced Study, Princeton, NJ 08540; [email protected] (Submitted 30 April 2000) We compute the joint constraints on ten cosmological parameters from the latest CMB measure- ments. The lack of a significant second acoustic peak in the latest Boomerang data favors models with more baryons than Big Bang nucleosynthesis predicts, almost independently of what prior information is included. The simplest flat inflation models with purely scalar scale-invariant fluctu- 2 ations prefer a baryon density 0:024 <hΩb < 0:042 and a total (hot + cold) dark matter density 2 0:16 <h Ωb < 0:51 at 95% confidence, and allow reionization no earlier than z ∼ 30. One of the main challenges in modern cosmology is to have used the measured cosmic microwave background refine and test the standard model of structure formation (CMB) fluctuations to constrain subsets of these param- by precision measurements of its free parameters. The eters. CMB data has improved dramatically since fluctu- cosmic matter budget involves at least the four parame- ations were first detected [9]. The measurement of a first ters Ωb,Ωcdm,Ων and ΩΛ, which give the percentages of acoustic peak at the degree scale [10], suggesting that the critical density corresponding to baryons, cold dark mat- Universe is flat (Ωk = 0), has now been beautifully con- ter, massive neutrinos and vacuum energy. A “budget firmed and improved by using the ground-breaking high deficit” Ωk ≡ 1 − Ωb − Ωcdm − Ων − ΩΛ manifests itself fidelity maps of the Boomerang experiment [11]. As can as spatial curvature. The description of the initial seed be seen in Figure 1, perhaps the most important new in- fluctuations predicted by inflation require at least four formation from Boomerang is its accurate measurements parameters, the amplitudes As & At and slopes ns & nt of the angular power spectrum C` on even smaller scales, of scalar and tensor fluctuations, respectively. Finally, out to multipole ` ∼ 600. The striking lack of a sig- the optical depth parameter τ quantifies when the first nificant second acoustic peak places strong constraints stars or quasars reionized the Universe and the Hubble on the cosmological parameters [8,11,12], making a new parameter h gives its current expansion rate. full-fledged analysis of all the CMB data very timely. In this Letter, we jointly constrain the following 10 cosmological parameters: τ,Ωk,ΩΛ, ns, nt, As,the tensor-to scalar ratio r ≡ At=As, and the physical matter 2 2 2 densities !b ≡ h Ωpb, !cdm ≡ h Ωcdm and !ν ≡ h Ων . The identity h = !cdm + !b + !ν =1 − Ωk − ΩΛ fixes the Hubble parameter. We use the 10-dimensional grid method described in [5]. In essence, this utilizes a tech- nique for accelerating the the CMBfast package [13] by a factor around 103 to compute theoretical power spectra on a grid in the 10-dimensional parameter space, fitting these models to the data and then using cubic interpo- lation of the resulting 10-dimensional likelihood function to marginalize it down to constraints on individual or pairs of parameters. We use the 77 data points shown in Figure 1, combining the 65 tabulated in [5] with the 12 new Boomerang points [11]. Our 95% confidence limits on the best constrained pa- rameters are summarized in Table 1. Figure 2 shows that CMB alone suggests that the Universe is either flat FIG. 1. The 77 band power measurements used. Circles ≡ show the new Boomerang points. The curve shows the simple (near the diagonal line Ωm +ΩΛ =1,whereΩm inflationary model with τ =Ωk = !ν = r =0,ΩΛ =0:19, Ωb +Ωcdm +Ων ) or closed (upper right). These con- !cdm =0:19, !b =0:03, ns =1. straints come largely from the location of the first peak, which is well-known to move to the right if the curva- During the past year or so, a number of papers [1–8] ture Ωk is increased [14]. Very closed models work only 1 because the first acoustic peak can also be moved to the τ 2Ω 2Ω right by increasing the tilt ns and bringing the large-scale h b h dm Ωk = 0 Ω = 0 Ω = 0 COBE signal back up with tensor fluctuations (gravity n = 1 k k s ns= 1 ns= 1 waves) [15,18]. Galaxy clustering constraints disfavor r= 0 r= 0 r= 0 such strong blue-tilting, and Figures 2 and 3 show that closing this loophole by barring gravity waves (r =0) favors curvature near zero and ns near unity. This is a striking success for the oldest and simplest inflation mod- Ω = 0 Ω Ω r k Λ k ns els, which make the three predictions =0,Ωk =0and ns= 1 = 0 r= 0 r= 0 ns = 1 [16,17]. Another important success for inflation is r that the first peak is so narrow — if the data had revealed the type of broad peak expected in many topological de- fect scenarios, none of the models in our grid would have provided an acceptable fit. Because of these tantalizing hints that “back to basics” inflation is correct, Table 1 FIG. 3. Marginalized : <h< : and Figure 3 include results assuming this inflation prior likelihoods assuming that 0 5 0 8 (95%) and the in- flationary priors shown above. 2 − σ limits are roughly where r =Ωk =0;ns =1. the curves drop beneath the dashed lines. The constraints in Table 1 are seen to be much more interesting than those before Boomerang [5], thanks to Λ 1.0 CMB alone new information on the scale of the second peak. CDM and neutrinos have indistinguishable effects on the CMB Ω CMB + h except for very light neutrinos (small !ν ), and the cur- CMB + h + r rent data still lacks the precision to detect this sub- tle difference. The predicted height ratio of the first two peaks therefore depends essentially on only three parameters [8,12]: ns, !b and !dm, where the total 0.5 ! ≡ ! ! CMB +SN h 1a dark matter density dm cdm + ν . Let us focus CMB alone on the constraints on these parameters. Increasing !b tends to boost the odd-numbered peaks (1, 3, etc.) at the expense of even ones (2, 4, etc.) [14], whereas in- creasing !dm suppresses all peaks (see the CMB movies at www:hep:upenn:edu=∼max or www:ias:edu=∼whu). 0.0 The low second peak can therefore be fit by either de- Vacuum density creasing the tilt ns or by increasing the baryon density 0.0 0.5 1.0 !b [8,12] compared to the usually assumed values ns ≈ 1, !b ≈ 0:02. As illustrated in Figure 4, this conclusion Matter density Ω is essentially independent of what priors are assumed. m However, reducing ns below 0.9 is seen to make things FIG. 2. The regions in the (Ωm; ΩΛ)-plane that are ruled worse again, as the first peak becomes too low relative to out at 95% are shown using (starting from the outside) no COBE-normalization. priors the prior that 0:5 <h<0:8 (95%) and the additional In short, there are two very simple ways of explain- constraint r = 0 The SN 1a constraints are from White98. ing the lack of a prominent second acoustic peak: more baryons or an red-tilted spectrum [8,12]. However, as we will now discuss, both of these solutions have problems Table 1 – Maximum-likelihood values and 95% confidence limits. of their own. The “inflation prior” for each parameter is indicated in Figure 3 Figure 5 shows that when more baryons are added, more dark matter is needed to keep the first peak height 10 free parameters Inflation prior constant. When the tilt ns is fixed by the inflation prior, Quantity Min Best Max Min Best Max the constraints on the remaining two parameters !dm τ 0.0 0.0 0.35 0.0 0.0 0.31 2 and !b are seen to become quite tight. Intriguingly, h Ωb .015 .05 − .024 .03 .045 2 the preferred baryon fraction is of the same order as h Ωdm 0 −−0.16 0.30 0.51 preferred by Big Bang nucleosynthesis, but nonetheless ΩΛ − 0.72 0.85 −0.44 .19 0.73 higher than the tight nucleosynthesis error bars [20,21] Ωk −−0.39 0.22 −0.24 0 0.15 !b =0:019 0:0024 allow. Even if the nucleosynthesis ns 0.71 1.53 − 0.84 1.0 1.16 2 error bars have somehow been underestimated so that permitted to be low enough to agree with nucleosynthesis > !b ∼ 0:03 as required by the CMB data plus simple in- for any value of the tilt ns, so the tilt solution may have flation is allowed, this solution may conflict with other worked using all the data merely because of the above- astrophysical constraints. For instance, X-ray observa- mentioned dilution effect. tions of clusters of galaxies can be used to determine the ratio of baryons to dark matter [22], and !b =0:03 can only be reconciled with these observations by having CMB + h + r Ωdm ∼ 0:6 which would conflict with the supernova 1a results and other estimates of the dark matter density CMB only [23]. CMB + h On the other hand, the tilt solution is no panacea ei- ther. In a wide range of inflationary models, the am- plitude of the tensor component is related to the tilt of the scalar spectrum, r =7(1− ns) [24].
Load more

Recommended publications
  • Maps of the Millimetre Sky from the Boomerang Experiment 35
    Maps of the Cosmos ASP Conference Series, Vol. 216, 2005 M. Colless, L. Staveley-Smith, R. Stathakis Maps of the Millimetre Sky from the BOOMERanG Experiment 1 P. de Bernardis", G. De Troia , M. Giacometti", A. Iacoangeli", 1 S. Masi", A. Melchiorri", F. Nati , F. Piacentini", G. Polenta", 2 S. Ricciardi", P. A. R. Ade , P. D. Mauskopf", A. Balbi3 , P. Cabella3 , 4 5 G. De Gasperis'', P. Natoli'', N. Vittorio'', J. J. Bock , J. R. Bond , C. R. Contaldi'', J. Borrill", A. Boscaleri", E. Pascale7,14 , W. C. Jones", A. E. Lange", P. Mason", V. V. Hristov", B. P. CriU8,9 , A. De-Oliveira 11 11 Costal", M. Tegmark!", K. Ganga , E. Hivon , T. Montroyl", T. Kisnerl", J E. Ruh112 , A. H. Jaffe l 3 , C. MacTavish14 , C. B. Netterfield'", D. Pogosyanl", S. Prunet'", and G. Romeo 17 1 Dipartimento di Fisica, Universita' La Sapienza, Roma, Italy 2 Dept. of Physics and Astronomy, Cardiff University, Wales, UK 3 Dipartimento di Fisica, Universita' di Tor Vergata, Roma, Italy 4 Jet Propulsion Laboratory, Pasadena, CA, USA 5 CITA, University of Toronto, Canada 6 NERSC, LBNL, Berkeley, CA, USA 7 IFAC-CNR, Firenze, Italy 8 California Institute of Technology, Pasadena, CA, USA 9 CSU Dominguez Hills, Carson, CA, USA 10 Phys. Dept. University of Pennsylvanya, Philadelphia, PA, USA 11 IPAC, CalTech, Pasadena, CA, USA 12 Physics Department, CWRU, Cleveland, OH, USA 13 Astrophysics Group, Imperial College, London, UK 14 Depts. of Physics and Astronomy, University of Toronto, Canada 15 Physics Dept., University of Alberta, Alberta, Canada 16 Institut d'Astrophysique, Paris, France 17 Istituto Nazionale di Geofisica, Roma, Italy Abstract.
    [Show full text]
  • The Theory of Anisotropies in the Cosmic Microwave Background
    TACMB-1: The Theory of Anisotropies in the Cosmic Microwave Background: Martin White and J.D. Cohn Dept. of Astronomy 601 Campbell Hall UC Berkeley Berkeley, CA 94720-3411 USA Abstract This Resource Letter provides a guide to the literature on the theory of anisotropies in the cosmic microwave background. Journal articles, web pages, and books are cited for the following topics: discovery, cosmological origin, early work, recombination, general CMB anisotropy references, primary CMB anisotropies (numerical, analytical work), secondary effects, Sunyaev-Zel’dovich effect(s), lensing, reionization, polarization, gravity waves, defects, topology, origin of fluctuations, development of fluctuations, inflation and other ties to particle physics, parameter estimation, recent constraints, web resources, foregrounds, observations and observational issues, and gaussianity. Introduction The cosmic microwave background (CMB) radiation is a relic of a time when the universe was hot and dense, and as such it encodes a wealth of information about the early universe and the formation of the large-scale structure we see in the universe today. The very existence of the CMB is one of the four pillars of the hot big bang cosmology. That the spectrum [7, 8, 9] is the best measured black body spectrum in nature provides stringent constraints on its origin and on any injection of energy at early times [14]. Perhaps the most exciting and active area of CMB research, however, is the study of its anisotropies: the small fluctuations in intensity from point to point across the sky. As we shall discuss below, these anisotropies provide us with a snapshot of the conditions in the universe about 300, 000 years after the big bang, when the universe was a simpler place.
    [Show full text]
  • A MEASUREMENT of Ω from the NORTH AMERICAN TEST FLIGHT of Boomerang A
    Preprint typeset using LATEX style emulateapj v. 04/03/99 A MEASUREMENT OF Ω FROM THE NORTH AMERICAN TEST FLIGHT OF Boomerang A. Melchiorri1;2;9, P.A.R. Ade3, P. de Bernardis1,J.J.Bock4;5, J. Borrill6;7,A. Boscaleri8,B.P.Crill4,G.DeTroia1,P.Farese10,P.G.Ferreira9;11;12,K.Ganga4;13, G. de Gasperis2, M. Giacometti1,V.V.Hristov4,A.H.Jaffe6, A.E. Lange4,S.Masi1, P.D. Mauskopf14,L.Miglio1;15,C.B.Netterfield15,E.Pascale8,F.Piacentini1,G. Romeo16, J.E. Ruhl10 and N. Vittorio2 1 Dipartimento di Fisica, Universita' La Sapienza, Roma, Italy 2 Dipartimento di Fisica, Universita' Tor Vergata, Roma, Italy 3 Queen Mary and Westfield College, London, UK 4 California Institute of Technology, Pasadena, CA, USA 5 Jet Propulsion Laboratory, Pasadena, CA, USA 6 Center for Particle Astrophysics, University of California, Berkeley, CA, USA 7 National Energy Research Scientific Computing Center, LBNL, Berkeley, CA, USA 8 IROE-CNR, Firenze, Italy 9 Dept. de Physique Theorique, Universite de Geneve, Switzerland 10 Dept. of Physics, Univ. of California, Santa Barbara, CA, USA 11 CENTRA, IST, Lisbon, Portugal 12 Theory Division, CERN, Geneva, Switzerland 13 Physique Corpusculaire et Cosmologie, College de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France 14 Dept. of Physics and Astronomy, University of Massachussets, Amherst, MA, USA 15 Depts. of Physics and Astronomy, University of Toronto, Canada 16 Istituto Nazionale di Geofisica, Roma, Italy ABSTRACT We use the angular power spectrum of the Cosmic Microwave Background, measured during the North American test flight of the Boomerang experiment, to constrain the geometry of the universe.
    [Show full text]
  • Astrophysics and Cosmology
    ASTROPHYSICS AND COSMOLOGY J. GarcÂõa-Bellido Theoretical Physics Group, Blackett Laboratory, Imperial College of Science, Technology and Medicine, Prince Consort Road, London SW7 2BZ, U.K. Abstract These notes are intended as an introductory course for experimental particle physicists interested in the recent developments in astrophysics and cosmology. I will describe the standard Big Bang theory of the evolution of the universe, with its successes and shortcomings, which will lead to inflationary cosmology as the paradigm for the origin of the global structure of the universe as well as the origin of the spectrum of density perturbations responsible for structure in our local patch. I will present a review of the very rich phenomenology that we have in cosmology today, as well as evidence for the observational revolution that this field is going through, which will provide us, in the next few years, with an accurate determination of the parameters of our standard cosmological model. 1. GENERAL INTRODUCTION Cosmology (from the Greek: kosmos, universe, world, order, and logos, word, theory) is probably the most ancient body of knowledge, dating from as far back as the predictions of seasons by early civiliza- tions. Yet, until recently, we could only answer to some of its more basic questions with an order of mag- nitude estimate. This poor state of affairs has dramatically changed in the last few years, thanks to (what else?) raw data, coming from precise measurements of a wide range of cosmological parameters. Further- more, we are entering a precision era in cosmology, and soon most of our observables will be measured with a few percent accuracy.
    [Show full text]
  • Arxiv:Astro-Ph/0004385V2 27 Jul 2000
    Boomerang returns unexpectedly1 Martin White Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 Douglas Scott and Elena Pierpaoli Department of Physics & Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 ABSTRACT Experimental study of the anisotropy in the cosmic microwave background (CMB) is gathering momentum. The eagerly awaited Boomerang results have lived up to expectations. They provide convincing evidence in favor of the standard paradigm: the Universe is close to flat and with primordial fluctuations which are redolent of inflation. Further scrutiny reveals something even more exciting however – two hints that there may be some unforeseen physical effects. Firstly the primary acoustic peak appears at slightly larger scales than expected. Although this may be explicable through a combination of mundane effects, we suggest it is also prudent to consider the possibility that the Universe might be marginally closed. The other hint is provided by a second peak which appears less prominent than expected. This may indicate one of a number of possibilities, including increased damping length or tilted initial conditions, but also breaking of coherence or features in the initial power spectrum. Further data should test whether the current concordance model needs only to be tweaked, or to be enhanced in some fundamental way. Subject headings: cosmology: theory – cosmic microwave background 1. Introduction The study of the Cosmic Microwave Background (CMB) anisotropy holds the promise of answering arXiv:astro-ph/0004385v2 27 Jul 2000 many of our fundamental questions about the Universe and the origin of the large-scale structure (see e.g. Bond 1996; Bennett, Turner & White 1997; Lawrence, Scott & White 1999).
    [Show full text]
  • A Mathematical Appendix
    381 A Mathematical Appendix A.1 Selected Formulae “Don’t worry about your difficulties in mathematics; I can assure you that mine are still greater.” Albert Einstein The solution of physics problems often involves mathemat- ics. In most cases nature is not so kind as to allow a precise mathematical treatment. Many times approximations are not only rather convenient but also necessary, because the gen- eral solution of specific problems can be very demanding and sometimes even impossible. In addition to these approximations, which often involve power series, where only the leading terms are relevant, ba- sic knowledge of calculus and statistics is required. In the following the most frequently used mathematical aids shall be briefly presented. 1. Power Series Binomial expansion: binomial expansion (1 ± x)m = m(m − 1) m(m − 1)(m − 2) 1 ± mx + x2 ± x3 +··· 2! 3! m(m − 1) ···(m − n + 1) + (±1)n xn +··· . n! For integer positive m this series is finite. The coefficients are binomial coefficients m(m − 1) ···(m − n + 1) m = . n! n If m is not a positive integer, the series is infinite and con- vergent for |x| < 1. This expansion often provides a simpli- fication of otherwise complicated expressions. 382 A Mathematical Appendix A few examples for most commonly used binomial ex- pansions: examples 1 1 1 5 (1 ± x)1/2 = 1 ± x − x2 ± x3 − x4 ±··· , for binomial expansions 2 8 16 128 − 1 3 5 35 (1 ± x) 1/2 = 1 ∓ x + x2 ∓ x3 + x4 ∓··· , 2 8 16 128 − (1 ± x) 1 = 1 ∓ x + x2 ∓ x3 + x4 ∓··· , (1 ± x)4 = 1 ± 4x + 6x2 ± 4x3 + x4 finite .
    [Show full text]
  • A Measurement of Omega from the North American Test Flight Of
    A Preprint typeset using L TEX style emulateapj v. 04/03/99 A MEASUREMENT OF Ω FROM THE NORTH AMERICAN TEST FLIGHT OF Boomerang A. Melchiorri1,2,9, P.A.R. Ade3, P. de Bernardis1, J.J. Bock4,5, J. Borrill6,7, A. Boscaleri8, B.P. Crill4, G. De Troia1, P. Farese10, P. G. Ferreira9,11,12, K. Ganga4,13, G. de Gasperis2, M. Giacometti1, V.V. Hristov4, A. H. Jaffe6, A.E. Lange4, S. Masi1, P.D. Mauskopf14, L. Miglio1,15, C.B. Netterfield15, E. Pascale8, F. Piacentini1, G. Romeo16, J.E. Ruhl10 and N. Vittorio2 1 Dipartimento di Fisica, Universita’ La Sapienza, Roma, Italy 2 Dipartimento di Fisica, Universita’ Tor Vergata, Roma, Italy 3 Queen Mary and Westfield College, London, UK 4 California Institute of Technology, Pasadena, CA, USA 5 Jet Propulsion Laboratory, Pasadena, CA, USA 6 Center for Particle Astrophysics, University of California, Berkeley, CA, USA 7 National Energy Research Scientific Computing Center, LBNL, Berkeley, CA, USA 8 IROE-CNR, Firenze, Italy 9 Dept. de Physique Theorique, Universite de Geneve, Switzerland 10 Dept. of Physics, Univ. of California, Santa Barbara, CA, USA 11 CENTRA, IST, Lisbon, Portugal 12 Theory Division, CERN, Geneva, Switzerland 13 Physique Corpusculaire et Cosmologie, College de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05, France 14 Dept. of Physics and Astronomy, University of Massachussets, Amherst, MA, USA 15 Depts. of Physics and Astronomy, University of Toronto, Canada 16 Istituto Nazionale di Geofisica, Roma, Italy ABSTRACT We use the angular power spectrum of the Cosmic Microwave Background, measured during the North American test flight of the Boomerang experiment, to constrain the geometry of the universe.
    [Show full text]
  • A ¯At Universe from High-Resolution Maps of the Cosmic Microwave Background Radiation
    articles A ¯at Universe from high-resolution maps of the cosmic microwave background radiation P. de Bernardis1,P.A.R.Ade2, J. J. Bock3, J. R. Bond4, J. Borrill5,12, A. Boscaleri6, K. Coble7, B. P. Crill8, G. De Gasperis9, P. C. Farese7, P. G. Ferreira10, K. Ganga8,11, M. Giacometti1, E. Hivon8, V. V. Hristov8, A. Iacoangeli1, A. H. Jaffe12, A. E. Lange8, L. Martinis13, S. Masi1, P. V. Mason8, P. D. Mauskopf14,15, A. Melchiorri1, L. Miglio16, T. Montroy7, C. B. Netter®eld16, E. Pascale6, F. Piacentini1, D. Pogosyan4, S. Prunet4,S.Rao17, G. Romeo17, J. E. Ruhl7, F. Scaramuzzi13, D. Sforna1 & N. Vittorio9 ............................................................................................................................................................................................................................................................................ The blackbody radiation left over from the Big Bang has been transformed by the expansion of the Universe into the nearly isotropic 2.73 K cosmic microwave background. Tiny inhomogeneities in the early Universe left their imprint on the microwave background in the form of small anisotropies in its temperature. These anisotropies contain information about basic cosmological parameters, particularly the total energy density and curvature of the Universe. Here we report the ®rst images of resolved structure in the microwave background anisotropies over a signi®cant part of the sky. Maps at four frequencies clearly distinguish the microwave background from foreground emission. We compute the angular power spectrum of the microwave background, and ®nd a peak at Legendre multipole l peak 197 6 6, with an amplitude DT 200 69 6 8 mK. This is consistent with that expected for cold dark matter models in a ¯at (euclidean) Universe, as favoured by standard in¯ationary models.
    [Show full text]
  • Evidence for a Flat Universe from the North American Flight Of
    Evidence for a Flat Universe from the North American Flight of BOOMERANG 2 3 1;4 5;6 7 8 B.P. Crill1 , P.A.R. Ade , P. de Bernardis , J.J. Bock , J. Borrill , A. Boscaleri , G. de Gasperis ,G.de 9 10;11 12;13 3 14 1 Troia3 , P. Farese , P.G. Ferreira , K. Ganga , M. Giacometti , S. Hanany , E.F. Hivon , V.V. 3 5 1 15 3 16;17 Hristov 1 , A. Iacoangeli , A.H. Jaffe , A.E. Lange , A.T. Lee , S. Masi , P. D. Mauskopf ,A. ;8;18 3 3 9 19 7 3 Melchiorri3 , F. Melchiorri , L. Miglio , T. Montroy , C.B. Netterfield , E. Pascale , F. Piacentini , 20 9 15 21 15 P.L. Richards15 , G. Romeo , J.E. Ruhl , E. Scannapieco , F. Scaramuzzi , R. Stompor , and N. Vittorio 8 1 California Institute of Technology, Pasadena, CA, USA 2 Queen Mary and Westfield College, London, UK 3 Dipartmento di Fisica, Universita’ di Roma “La Sapienza”, Roma, Italy 4 Jet Propulsion Laboratory, Pasadena, CA, USA 5 Center for Particle Astrophysics, University of California, Berkeley, CA, USA 6 National Energy Research Scientific Computing Center, LBNL, Berkeley, CA, USA 7 IROE-CNR, Firenze, Italy 8 Dipartmento di Fisica, Secundo Universita’ di Roma “Tor Vergata”, Roma, Italy 9 Department of Physics, University of California, Santa Barbara, CA, USA 10 CENTRA, IST, Lisbon, Portugal 11 Theory Division, CERN, Geneva, Switzerland 12 Physique Corpusculaire et Cosmologie, College de France, Paris, France 13 IPAC, Pasadena, CA, USA 14 Department of Physics, University of Minnesota, Minneapolis, MN, USA 15 Department of Physics, University of California, Berkeley, CA, USA 16 Deptarment of Physics and Astronomy, University of Massachussets, Amherst, MA, USA 17 Department of Physics and Astronomy, University of Wales, Cardiff, UK 18 Departement de Physique Theorique, Univeriste de Geneve, Switzerland 19 Departments of Physics and Astronomy, University of Toronto, Toronto, Canada 20 Instituto Nazionale di Geofisica, Roma, Italy 21 ENEA, Frascati, Italy Abstract BOOMERANG is a millimeter- and submillimeter-wave telescope designed to observe the Cosmic Microwave Background from a stratospheric balloon above Antarctica.
    [Show full text]
  • Space Spectroscopy of the Cosmic Microwave
    ^-space spectroscop Cosmie th f yo c Microwave Background wit BOOMERane hth G experiment P. de Bernardis1, RA.R. Ade2, JJ. Bock3, J.R. Bond4, J. Borrill5, A. Boscaleri6, K. Coble7, C.R. Contaldi4, B.R GrillGasperise D . Troia8e ,G D . 9Farese. ,G 1 ,P 7, K. Ganga Giacometti. 10,M Hivon. 1,E 10, V.V. Hristov lacoangel. 8,A i l A.H. Jaffe11, W.C. Jones8, A.E. Lange Martinis. 8,L 12Masi. ,S Mason. 1,P 8, P.O. Mauskopf Melchiorri. 13A , 14Natoli. ,P Montroy. 9,T 7, C.B. Netterfield15, E. Pascale6, E Piacentini1, D. Pogosyan4, G. Polenta1, E Pongetti16, S. Prunet4, G. Romeo16, I.E. Ruhl 7Scaramuzzi,E Vittorio. 12,N 14 1 Dipartimento Fisica,di Universitd Sapienza,La Roma, P.le Mow,A. 00185,2, Italy. 2 Queen Maryand Westfield College, London, UK. 3 Jet Propulsion Laboratory, Pasadena, CA, USA.4 C.I.T.A., University of Toronto, Canada.5 N.E.R.S.C., LBNL, Berkeley, CA, USA. 6IROE-CNR, Firenze, Italy.1 Dept. of Physics, Univ. of California, Santa Barbara, CA, USA. 8 California Institute of Technology, Pasadena, CA, USA. 9 Department of Physics, Second University of Rome, Italy. 10IPAC, Caltech, Pasadena, CA, USA. u Department of Astronomy, Space Sciences Centerand Particlefor Lab Astrophysics, University ofCA, Berkeley, 94720CA USA. u ENEA, Frascati, Italy. ° Dept. of Physics and Astronomy, Cardiff University, Cardiff CF24 3YB, Wales, UK. 14 Nuclear and Astrophysics Laboratory, University of Oxford, Keble Road, Oxford, OX3RH, UK.15 Depts. of Physics and Astronomy, University of Toronto, Canada.16 Istituto Nazionale di Geofisica, Roma, Italy.
    [Show full text]
  • Reexamining the Constraint on the Helium Abundance From
    astro-ph/0601099 January 2006 Reexamining the Constraint on the Helium Abundance from CMB Kazuhide Ichikawa and Tomo Takahashi Institute for Cosmic Ray Research, University of Tokyo Kashiwa 277-8582, Japan (June 18, 2018) Abstract We revisit the constraint on the primordial helium mass fraction Yp from obser- vations of cosmic microwave background (CMB) alone. By minimizing χ2 of recent CMB experiments over 6 other cosmological parameters, we obtained rather weak constraints as 0.17 ≤ Yp ≤ 0.52 at 1σ C.L. for a particular data set. We also study the future constraint on cosmological parameters when we take account of the pre- diction of the standard big bang nucleosynthesis (BBN) theory as a prior on the helium mass fraction where Yp can be fixed for a given energy density of baryon. We discuss the implications of the prediction of the standard BBN on the analysis of CMB. arXiv:astro-ph/0601099v2 5 Apr 2006 1 Introduction Recent precise cosmological observations such as WMAP [1] push us toward the era of so-called precision cosmology. In particular, the combination of the data from cosmic microwave background (CMB), large scale structure, type Ia supernovae and so on can severely constrain the cosmological parameters such as the energy density of baryon, cold dark matter and dark energy, the equation of state for dark energy, the Hubble parameter, the amplitude and the scale dependence of primordial fluctuation. Among the various cosmological parameters, the primordial helium mass fraction Yp is the one which has been mainly discussed in the context of big bang nucleosynthesis (BBN) but not that of CMB so far.
    [Show full text]
  • B1487(01)Quarks FM.I-Xvi
    Connecting Quarks with the Cosmos Eleven Science Questions for the New Century Committee on the Physics of the Universe Board on Physics and Astronomy Division on Engineering and Physical Sciences THE NATIONAL ACADEMIES PRESS Washington, D.C. www.nap.edu THE NATIONAL ACADEMIES PRESS 500 Fifth Street, N.W. Washington, DC 20001 NOTICE: The project that is the subject of this report was approved by the Govern- ing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineer- ing, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. This project was supported by Grant No. DE-FG02-00ER41141 between the Na- tional Academy of Sciences and the Department of Energy, Grant No. NAG5-9268 between the National Academy of Sciences and the National Aeronautics and Space Administration, and Grant No. PHY-0079915 between the National Academy of Sciences and the National Science Foundation. Any opinions, findings, and conclu- sions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that pro- vided support for the project. International Standard Book Number 0-309-07406-1 Library of Congress Control Number 2003100888 Additional copies of this report are available from the National Academies Press, 500 Fifth Street, N.W., Lockbox 285, Washington, DC 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet, http://www.nap.edu and Board on Physics and Astronomy, National Research Council, NA 922, 500 Fifth Street, N.W., Washington, DC 20001; Internet, http://www.national-academies.org/bpa.
    [Show full text]