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Schramm DN. Particle Physics and Inflationary Cosmology. Andrei Linde. Harwood, New York, 1990. xviii, 362 pp., illus. $60; paper, $29. Contemporary Concepts in Physics, vol. 5. Translated from the Russian by Marc Damashek. Science 2010. [PMID: 17746929 DOI: 10.1126/science.250.4983.1021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Copi CJ, Olive KA, Schramm DN. Implications of a primordial origin for the dispersion in D/H in quasar absorption systems. Proc Natl Acad Sci U S A 1998; 95:2758-60. [PMID: 9501162 PMCID: PMC19641 DOI: 10.1073/pnas.95.6.2758] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We explore the difficulties with a primordial origin of variations of D/H in quasar absorption systems. In particular we examine options such as a very large-scale inhomogeneity in the baryon content of the universe. We show that very large-scale (much larger than 1 Mpc) isocurvature perturbations are excluded by current cosmic microwave background observations. Smaller-scale ad hoc perturbations (approximately 1 Mpc) still may lead to a large dispersion in primordial abundances but are subject to other constraints.
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Affiliation(s)
- C J Copi
- Case-Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7079, USA
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Affiliation(s)
- D N Schramm
- Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637-1433, USA
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Abstract
With the advent of the new extragalactic deuterium observations, Big Bang nucleosynthesis (BBN) is on the verge of undergoing a transformation. In the past, the emphasis has been on demonstrating the concordance of the BBN model with the abundances of the light isotopes extrapolated back to their primordial values by using stellar and galactic evolution theories. As a direct measure of primordial deuterium is converged upon, the nature of the field will shift to using the much more precise primordial D/H to constrain the more flexible stellar and galactic evolution models (although the question of potential systematic error in 4He abundance determinations remains open). The remarkable success of the theory to date in establishing the concordance has led to the very robust conclusion of BBN regarding the baryon density. This robustness remains even through major model variations such as an assumed first-order quark-hadron phase transition. The BBN constraints on the cosmological baryon density are reviewed and demonstrate that the bulk of the baryons are dark and also that the bulk of the matter in the universe is nonbaryonic. Comparison of baryonic density arguments from Lyman-alpha clouds, x-ray gas in clusters, and the microwave anisotropy are made.
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Affiliation(s)
- D N Schramm
- University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637, USA.
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Abstract
Recently, a possible clustering of a subset of observed ultra-high energy cosmic rays above approximately 40 EeV (4 x 10(19) eV) in pairs near the supergalactic plane was reported. We show that a confirmation of this effect would provide information on the origin and nature of these events and, in case of charged primaries, imply interesting constraints on the extragalactic magnetic field. Possible implications for the most common models of ultra-high energy cosmic ray production in the literature are discussed.
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Affiliation(s)
- G Sigl
- Department of Astronomy and Astrophysics, Enrico Fermi Institute, University of Chicago, Chicago, IL 60637-1433, USA
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Abstract
Observers have found a small number of lithium-depleted halo stars in the temperature range of the Spite plateau. The current status of the mass-loss hypothesis for producing the observed lithium dip in Population (Pop) I stars is briefly discussed and extended to Pop II stars as a possible explanation for these halo objects. Based on detections of F-type main-sequence variables, mass loss is assumed to occur in a narrow temperature region corresponding to this "instability strip." As Pop II main-sequence stars evolve to the blue, they enter this narrow temperature region, then move back through the lower temperature area of the Spite plateau. If 0.05 M. (solar mass) or more have been lost, they will show lithium depletion. This hypothesis affects the lithium-to- beryllium abundance, the ratio of high- to low-lithium stars, and the luminosity function. Constraints on the mass-loss hypothesis due to these effects are discussed. Finally, mass loss in this temperature range would operate in stars near the turnoff of metal-poor globular clusters, resulting in apparent ages 2 to 3 Gyr (gigayears) older than they actually are.
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Affiliation(s)
- D S Dearborn
- Lawrence Livermore National Laboratory, University of California, L-58, P.O. Box 808, Livermore, CA 94550, USA
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Cheng B, Olinto AV, Schramm DN, Truran JW. Constraints on the strength of primordial magnetic fields from big bang nucleosynthesis reexamined. Phys Rev D Part Fields 1996; 54:4714-4718. [PMID: 10021158 DOI: 10.1103/physrevd.54.4714] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Sigl G, Jedamzik K, Schramm DN, Berezinsky VS. Helium photodisintegration and nucleosynthesis: Implications for topological defects, high energy cosmic rays, and massive black holes. Phys Rev D Part Fields 1995; 52:6682-6693. [PMID: 10019209 DOI: 10.1103/physrevd.52.6682] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Schramm DN, Rosner R, Luo X, Klemperer W. On the possibility of coherently stimulated recombination and cosmological structure generation: cosmological consequences. Proc Natl Acad Sci U S A 1995; 92:6171-4. [PMID: 11607553 PMCID: PMC41664 DOI: 10.1073/pnas.92.13.6171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Given a specific physical mechanism for instabilities during cosmological recombination discussed in an earlier paper, we examine the nonlinear growth of density structures to form fractal-like structural patterns out to the horizon scale at that epoch (approximately 200 Mpc today). A model for such fractal patterns is presented. Such effects could explain observed large-scale structure patterns and the formation of objects at high z, while keeping microwave background anisotropies at the observed minimal levels. We also discuss possible microwave background implications of such a transition and note a potentially observable spectral signature at lambda approximately 0.18 mm as well as a weak line near the peak in the microwave background.
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Affiliation(s)
- D N Schramm
- Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637, USA
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Klemperer W, Luo X, Rosner R, Schramm DN. On the possibility of coherently stimulated recombination and cosmological structure generation: recombination instability. Proc Natl Acad Sci U S A 1995; 92:6166-70. [PMID: 11607552 PMCID: PMC41663 DOI: 10.1073/pnas.92.13.6166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Possible instabilities during cosmological recombination may produce an epoch of nonlinear density growth and fractal-like structural patterns out to the horizon scale at that epoch (approximately 200 Mpc today). With this motivation, we examine the consequences of the change in effective radiative recombination reaction rate coefficients produced by intense stimulated emission. The proton-electron recombination is considered as a natural laser, leading to the formation of spatially nonuniform distributions of neutral matter earlier than the recombination epoch.
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Affiliation(s)
- W Klemperer
- Department of Chemical Physics, Harvard University, Cambridge, MA 02138, USA
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Abstract
For almost 30 years, the predictions of big-bang nucleosynthesis have been used to test the big-bang model to within a fraction of a second of the bang. The agreement between the predicted and observed abundances of deuterium, helium-3, helium-4, and lithium-7 confirms the standard cosmology model and allows accurate determination of the baryon density, between 1.7 x 10(-31) and 4.1 x 10(-31) grams per cubic centimeter (corresponding to about 1 to 15 percent of the critical density). This measurement of the density of ordinary matter is pivotal to the establishment of two dark-matter problems: (i) most of the baryons are dark, and (ii) if the total mass density is greater than about 15 percent of the critical density, as many determinations indicate, the bulk of the dark matter must be "non-baryonic," composed of elementary particles left from the earliest moments.
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Affiliation(s)
- C J Copi
- Department of Physics, University of Chicago, IL 60637-1433
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Abstract
We examine the possibility that a nearby supernova explosion could have caused one or more of the mass extinctions identified by paleontologists. We discuss the possible rate of such events in the light of the recent suggested identification of Geminga as a supernova remnant less than 100 parsec (pc) away and the discovery of a millisecond pulsar about 150 pc away and observations of SN 1987A. The fluxes of gamma-radiation and charged cosmic rays on the Earth are estimated, and their effects on the Earth's ozone layer are discussed. A supernova explosion of the order of 10 pc away could be expected as often as every few hundred million years and could destroy the ozone layer for hundreds of years, letting in potentially lethal solar ultraviolet radiation. In addition to effects on land ecology, this could entail mass destruction of plankton and reef communities, with disastrous consequences for marine life as well. A supernova extinction should be distinguishable from a meteorite impact such as the one that presumably killed the dinosaurs at the "KT boundary." The recent argument that the KT event was exceedingly large and thus quite rare supports the need for other catastrophic events.
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Affiliation(s)
- J Ellis
- Theoretical Physics Division, European Organization for Nuclear Research, Geneva, Switzerland
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Abstract
Some 15 billion years ago the universe emerged from a hot, dense sea of matter and energy. As the cosmos expanded and cooled, it spawned galaxies, stars, planets and life.
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Cheng B, Schramm DN, Truran JW. Constraints on the strength of a primordial magnetic field from big bang nucleosynthesis. Phys Rev D Part Fields 1994; 49:5006-5018. [PMID: 10016811 DOI: 10.1103/physrevd.49.5006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Shi X, Schramm DN, Fields BD. Constraints on neutrino oscillations from big bang nucleosynthesis. Phys Rev D Part Fields 1993; 48:2563-2572. [PMID: 10016504 DOI: 10.1103/physrevd.48.2563] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Luo X, Schramm DN. Testing for the Gaussian nature of cosmological density perturbations through the three-point temperature correlation function. Phys Rev Lett 1993; 71:1124-1127. [PMID: 10055456 DOI: 10.1103/physrevlett.71.1124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Abstract
Primordial nucleosynthesis provides (with the microwave background radiation) one of the two quantitative experimental tests of the hot Big Bang cosmological model (versus alternative explanations for the observed Hubble expansion). The standard homogeneous-isotropic calculation fits the light element abundances ranging from 1H at 76% and 4He at 24% by mass through 2H and 3He at parts in 105 down to 7Li at parts in 1010. It is also noted how the recent Large Electron Positron Collider (and Stanford Linear Collider) results on the number of neutrinos (Nnu) are a positive laboratory test of this standard Big Bang scenario. The possible alternate scenario of quark-hadron-induced inhomogeneities is also discussed. It is shown that when this alternative scenario is made to fit the observed abundances accurately, the resulting conclusions on the baryonic density relative to the critical density (Omegab) remain approximately the same as in the standard homogeneous case, thus adding to the robustness of the standard model and the conclusion that Omegab approximately 0.06. This latter point is the driving force behind the need for nonbaryonic dark matter (assuming total density Omegatotal = 1) and the need for dark baryonic matter, since the density of visible matter Omegavisible < Omegab. The recent Population II B and Be observations are also discussed and shown to be a consequence of cosmic ray spallation processes rather than primordial nucleosynthesis. The light elements and Nnu successfully probe the cosmological model at times as early as 1 sec and a temperature (T) of approximately 10(10) K (approximately 1 MeV). Thus, they provided the first quantitative arguments that led to the connections of cosmology to nuclear and particle physics.
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Affiliation(s)
- D N Schramm
- Astronomy and Astrophysics Centers 140, University of Chicago, Chicago, IL 60637, USA
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Schramm DN. Physical cosmology. Introduction to papers presented at a colloquium "Physical Cosmology," March 27-28, 1992, National Academy of Sciences, Irvine, CA. Proc Natl Acad Sci U S A 1993; 90:4765. [PMID: 11607382 PMCID: PMC46595 DOI: 10.1073/pnas.90.11.4765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- D N Schramm
- Deparment of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637, USA
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Aharonian FA, Bhattacharjee P, Schramm DN. Photon/proton ratio as a diagnostic tool for topological defects as the sources of extremely high-energy cosmic rays. Phys Rev D Part Fields 1992; 46:4188-4192. [PMID: 10014798 DOI: 10.1103/physrevd.46.4188] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Shi X, Schramm DN, Bahcall JN. Monte Carlo exploration of Mikheyev-Smirnov-Wolfenstein solutions to the solar neutrino problem. Phys Rev Lett 1992; 69:717-720. [PMID: 10047015 DOI: 10.1103/physrevlett.69.717] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Bhattacharjee P, Hill CT, Schramm DN. Grand unified theories, topological defects, and ultrahigh-energy cosmic rays. Phys Rev Lett 1992; 69:567-570. [PMID: 10046974 DOI: 10.1103/physrevlett.69.567] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Peebles PJE, Turner EC, Schramm DN, Kron RG. Big Bang contd.. . Nature 1992. [DOI: 10.1038/357288a0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Observations of galaxy-galaxy and cluster-cluster correlations as well as other large-scale structure can be fit with a "limited" fractal with dimension D approximately 1.2. This is not a "pure" fractal out to the horizon: the distribution shifts from power law to random behavior at some large scale. If the observed patterns and structures are formed through an aggregation growth process, the fractal dimension D can serve as an interesting constraint on the properties of the stochastic motion responsible for limiting the fractal structure. In particular, it is found that the observed fractal should have grown from two-dimensional sheetlike objects such as pancakes, domain walls, or string wakes. This result is generic and does not depend on the details of the growth process.
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Fuller GM, Schramm DN. Late-phase-transition-induced fluctuations in the cosmic neutrino distribution and the formation of structure in the Universe. Phys Rev D Part Fields 1992; 45:2595-2600. [PMID: 10014649 DOI: 10.1103/physrevd.45.2595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Hill CT, Schramm DN, Walker TP. Ultra-high-energy cosmic rays from superconducting cosmic strings. Phys Rev D Part Fields 1987; 36:1007-1016. [PMID: 9958264 DOI: 10.1103/physrevd.36.1007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Hill CT, Schramm DN, Walker TP. Implications of the ultrahigh-energy cosmic-ray spectrum observed by the Fly's Eye detector. Phys Rev D Part Fields 1986; 34:1622-1625. [PMID: 9957325 DOI: 10.1103/physrevd.34.1622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Dearborn DS, Schramm DN, Steigman G. Astrophysical constraints on the couplings of axions, majorons, and familons. Phys Rev Lett 1986; 56:26-29. [PMID: 10032520 DOI: 10.1103/physrevlett.56.26] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Schramm DN, Anders E, Chandrasekhar S, Palmer P, Parker E, Simpson JA. Astronomers' Petition. Science 1976; 191:1124. [PMID: 17781625 DOI: 10.1126/science.191.4232.1124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Affiliation(s)
- D N Schramm
- California Institute of Technology, Pasadena, USA
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Cosman ER, Schramm DN, Enge HA, Sperduto A, Paris CH. Nuclear-Reaction Studies in the Nickel Isotopes: TheNi61(p,p′)Ni61,Ni61(d,d′)Ni61, andNi60(d,p)Ni61Reactions. ACTA ACUST UNITED AC 1967. [DOI: 10.1103/physrev.163.1134] [Citation(s) in RCA: 52] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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