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The homogeneous big-bang nucleosynthesis yields of D, He-3, He-4, and Li-7 are computed taking into account recent measurements of the neutron mean-life as well as updates of several nuclear reaction rates which primarily affect the production of Li-7. The extraction of primordial abundances from observation and the likelihood that the primordial mass fraction of He-4, Y(sub p) is less than or equal to 0.24 are discussed. Using the primordial abundances of D + He-3 and Li-7 we limit the baryon-to-photon ratio (eta in units of 10 exp -10) 2.6 less than or equal to eta(sub 10) less than or equal to 4.3; which we use to argue that baryons contribute between 0.02 and 0.11 to the critical energy density of the universe. An upper limit to Y(sub p) of 0.24 constrains the number of light neutrinos to N(sub nu) less than or equal to 3.4, in excellent agreement with the LEP and SLC collider results. We turn this argument around to show that the collider limit of 3 neutrino species can be used to bound the primordial abundance of He-4: 0.235 less than or equal to Y(sub p) less than or equal to 0.245. Olive, Keith A. and Schramm, David N. and Steigman, Gary and Walker, Terry P. Unspecified Center NASA-CR-186256, NAS 1.26:186256, FERMILAB-PUB-89/262-A, CFA-89-2985, UMN-TH-816/89 NASG-931; DE-AC02-83ER-40105; DE-AC02-76ER-01545; NSF AST-88-20595; NAGW-1321; NAGW-1340...
The book reviews theories of nucleosynthesis in big-bang cosmology. It introduces the standard model of cosmology, astronuclear reactions, numerical techniques for nucleosynethsis, and describes in detail the theories that go beyond the standard models, enabling readers to grasp the physics of big-bang nucleosynthesis on the basis of cosmology, general relativity and nuclear physics. In addition, the authors provide insights into the theoretical constrains required by observations. As a consequence, readers find out that big-bang nucleosynthesis still has windows opened to another cosmology. Although the book focuses on highly advanced topics, it is concisely written and mathematical derivations are explained step-by-step, making it accessible to graduate readers. Thus it is a short monograph appealing to a variety of readers interested in nucleosynthesis of big-bang cosmology.
A reexamination of the effects of non-zero degeneracies on Big Bang Nucleosynthesis is made. As previously noted, non-trivial alterations of the standard model conclusions can be induced only if excess lepton numbers L sub i, comparable to photon number densities eta sub tau, are assumed (where eta sub tau is approx. 3 times 10(exp 9) eta sub b). Furthermore, the required lepton number densities (L sub i eta sub tau) must be different for upsilon sub e than for upsilon sub mu and epsilon sub tau. It is shown that this loophole in the standard model of nucleosynthesis is robust and will not vanish as abundance and reaction rate determinations improve. However, it is also argued that theoretically (L sub e) approx. (L sub mu) approx. (L sub tau) approx. eta sub b is much less than eta sub tau which would preclude this loophole in standard unified models. Olive, K. A. and Schramm, David N. and Thomas, D. and Walker, T. P. NASA-CR-188703, NAS 1.26:188703, FERMILAB-PUB-91/192-A NAGW-1340...
Physicists have devoted much effort to reproducing the conditions of the primordial universe in laboratory conditions in their quest to work out a comprehensive theory of the appearance and evolution of nuclear matter. Whether it be trying to recreate the predicted primordial state of high-energy density matter in which quarks and gluons are effectively deconfined - the so-called Quark Gluon Plasma (QGP) - or exploring the structure and reaction properties of very unstable nuclei in experiments using radioactive beams, they have striven to understand the events which characterized the Big Bang and the various nucleosynthesis mechanisms which occur in the stars. This book contains the proceedings of the 2010 Enrico Fermi summer school held in Varenna, Italy, in July 2010, and devoted to the present understanding of the primordial universe and the origin of the elements, as achieved by studying nuclei and their constituents in extreme regimes of energy and composition. Subjects covered include: QGP formation; exotic nuclei, their degrees of freedom from the ground state and the properties of the excited states; the complex, but appealing theory describing the supernovae explosion and neutron stars; dark energy and matter; Big Bang nucleosynthesis and energy and solar neutrino production; nuclear cosmochronology; beta and gamma decay relevant for the nucleosynthesis of heavy nuclei. The annual Enrico Fermi summer school is internationally renowned and this book will be of great interest to all those involved in the field of nuclear physics.
This book describes the origins and evolution of the chemical elements we and the cosmos are made of. The story starts with the discovery of the common elements on Earth and their subsequent discovery in space. How do we learn the composition of the distant stars? How did progress in quantum theory, nuclear physics, spectroscopy, stellar structure and evolution, together with observations of stars, converge to provide an incredibly detailed picture of the universe? How does research in the micro-world explain the macro-world? How does progress in one affect the other, or lack of knowledge in one inhibit progress in the other? In short, Shaviv describes how we discovered the various pieces of the jigsaw that form our present picture of the universe; and how we sometimes put these in the wrong place before finding in the right one. En route we meet some fascinating personalities and learn about heated controversies. Shaviv shows how science lurched from one dogma to the next, time and again shattering much of what had been considered solid knowledge, until eventually a stable understanding arose. Beginning with generally accepted science, the book ends in today’s terra incognita of nuclear physics, astrophysics and cosmology. A monumental work that will fascinate scientists, philosophers, historians and lay readers alike.
An examination and brief review is made of the effects of quark-hadron transistion induced fluctuations on Big Bang nucleosynthesis. It is shown that cosmologically critical densities in baryons are difficult to reconcile with observation, but the traditional baryon density constraints from homogeneous calculations might be loosened by as much as 50 percent, to 0.3 of critical density, and the limit on the number of neutrino flavors remains about N(sub nu) is less than or approximately 4. To achieve baryon densities of greater than or approximately 0.3 of critical density would require initial density contrasts R is much greater the 10(exp 3), whereas the simplest models for the transition seem to restrict R to less than of approximately 10(exp 2). Kurki-Suonio, Hannu and Matzner, Richard A. and Olive, Keith A. and Schramm, David N. Unspecified Center NASA-CR-186169, NAS 1.26:186169, FERMILAB-PUB-89/252-A NAGW-1340...