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Inflation and the Cosmic Microwave Background
Inflation and the Cosmic Microwave Background

... as it is. What in ation does is make the region from which the Universe emerged, very small. How small? is unknown (hence the question mark in Fig. 2), but small enough to allow the points in opposite sides of the sky (A and B in Fig. 4) to be in causal contact. The exponential expansion of in ation ...
Nuclear astrophysics: the unfinished quest for the origin of the
Nuclear astrophysics: the unfinished quest for the origin of the

... energy near 8.8 MeV per nucleon. There are 82 elements that have stable isotopes, all the way from H to Pb (except for Tc and Pm). Several dozen elements have only unstable isotopes, naturally abundant or artificially produced in nuclear physics laboratories (the super-heaviest nucleus discovered to ...
Effects of triple-α and C(α, γ )16 O reaction rates on the supernova
Effects of triple-α and C(α, γ )16 O reaction rates on the supernova

... The triple-α and 12 C(α, γ )16 O rates are the key nuclear reaction rates concerning He-burning in massive star evolution. As a consequence, explosive nucleosynthesis and the resulting supernova yields of a massive star would be influenced seriously by the two rates. We select four combinations from ...
Ch. 22
Ch. 22

... • What do we mean when we ask whether dark matter is ordinary or extraordinary matter? • Ordinary matter is made from protons, neutrons, and electrons; we refer to it as baryonic matter because protons and neutrons are both classified as baryons. However, the baryonic matter we have found does not a ...
Galactic chemical evolution of heavy elements: from Barium to
Galactic chemical evolution of heavy elements: from Barium to

... work of Mathews et al. (1992) needs to be revised, as quantitative yields are now available from detailed nucleosynthesis calculations based on TP-AGB models for different masses and metallicities, with updated reaction networks and neutron capture cross sections. In addition, as anticipated by Trur ...
chime
chime

... • across an octave in frequency (400-800MHz) • for between 5 minutes and hours (depending on Decl.) • with s timing resolution & accuracy ...
Document
Document

... – Take into account: – two p-p fusions per branch – weightings of each branch – 15 MeV per p-p fusion – Given number of fusions per m-3 calculated earlier, energy production rate ~ 120 Wm-3 ...
Interpretation of the evolution of universe through the consciousness
Interpretation of the evolution of universe through the consciousness

... space’ can never be considered really empty; subatomic particles can flit in and out of existence on energy borrowed from energy fields. The effects of these quantum fluctuations have been observed in atoms, and similar fluctuations during the inflation are thought to have produced the seeds around ...
an aluminum/calcium-rich, iron-poor, white dwarf star
an aluminum/calcium-rich, iron-poor, white dwarf star

... are of type DAZ—showing the presence of hydrogen and of elements heavier than helium. Our 2007 and 2010 observations covered the range 3130–5940 Å. The blue cross disperser was combined with a 1. 15 slit resulting in a spectral resolution of ∼40,000. Reduction procedures utilized two software pack ...
Star Wreck
Star Wreck

... and electrons. The explosion is associated with the energy release ∼ 1052 ...1053 erg, almost as grandiose as that of a supernova. As the gravity subsides at the onset of the explosion, the unleashed neutrons can decay into protons and electrons with an emission of neutrinos and gamma-rays. The emis ...
Ch 33) Astrophysics and Cosmology
Ch 33) Astrophysics and Cosmology

... galaxies as they appeared then, 13.4 billion years ago, which is when they emitted this light. The most distant galaxies were young and small and grew to become large galaxies by colliding and merging with other small galaxies. We examine the latest theories on how stars and galaxies form and evolve ...
15. Our Star - UC Berkeley Astronomy w
15. Our Star - UC Berkeley Astronomy w

... The Origin of the Atomic Elements The 92 atomic elements were all constructed in the centers of stars (except hydrogen, helium and lithium). ...
opportunities nuclear astrophysics
opportunities nuclear astrophysics

... remotest of galaxies. Moreover, the energy on which we depend for life originates in nuclear reactions at the center of the nearest star, our sun. Our understanding of these processes has developed greatly in the last 75 years. It was known early on that nuclear reactions must provide the energy for ...
Institute for Structure and Nuclear Astrophysics
Institute for Structure and Nuclear Astrophysics

... remotest of galaxies. Moreover, the energy on which we depend for life originates in nuclear reactions at the center of the nearest star, our sun. Our understanding of these processes has developed greatly in the last 75 years. It was known early on that nuclear reactions must provide the energy for ...
Element Segregation in Low Metallicity Stars and the Primordial
Element Segregation in Low Metallicity Stars and the Primordial

... which depends on the effective temperature, the age and the metallicity of the stars. This prediction is in contradiction with the observations of the lithium plateau in Pop II stars. However, as discussed above, the lithium profiles in the standard models present a maximum (Limax ) which remains re ...
Early Universe Cosmology Advanced String School 2014 Puri, India
Early Universe Cosmology Advanced String School 2014 Puri, India

... • Pressure free matter/dust, w = 0. Ordinary baryonic matter as well as dark matter fall into this category. Their energy density simply scales inversely to the volume of a given region of space, ρ ∝ a−3 , as expected. • Relativistic particles/radiation, w = 13 . The energy density of radiation or a ...
The Hubble Law
The Hubble Law

... slight blue-shift. Please note that it is space itself which expands in the Big Bang model. Galaxies are moved outward in this process. Much recent activity has involved detecting pulsating Cepheids in the large Virgo cluster of galaxies, about 50 million light years away. These galaxies have provid ...
Stellar Helium Burning in Other Universes: A
Stellar Helium Burning in Other Universes: A

... carbon abundance that is necessary for life, it is not known if such low carbon universes would be habitable. In addition, the triple alpha process is only necessary because 8 Be is unstable, and its binding energy is higher than two separate alpha particles by a difference of about 92 keV. The simi ...
Time After Time — Big Bang Cosmology and the Arrows
Time After Time — Big Bang Cosmology and the Arrows

... essential difference between the past and the future. The most basic known laws of nature do not contain this asymmetry. And yet, several arrows of time can be distinguished – at least ten, in fact. However, it is unclear whether any of them are fundamental or whether others can be reduced to these, ...
(S. Lloyd 2001) - Digilander
(S. Lloyd 2001) - Digilander

... The Margolus-Levitin theorem is a mathematical expression of the familiar fact that energy must be invested to change a system such as a quantum bit from one state to another. As an example, consider the process of flipping a bit in an NMR quantum computer. In NMR quantum computing, each nuclear spi ...
THE VIRTUAL INEVITABILITY OF SINGULARITIES IN
THE VIRTUAL INEVITABILITY OF SINGULARITIES IN

... c) Inflationary theory is the only one that will allow for either a “flat universe” or a large, homogeneous, open universe. Since these two scenarios are currently more explicative of universal conditions than the closed one, it would seem that inflationary theory is necessary to explain our univers ...
Solar System Deuterium/Hydrogen Ratio
Solar System Deuterium/Hydrogen Ratio

... C2H+2 + HD). They have calculated that the measured distribution of D/H ratios in most observed organic molecules corresponds to reaction durations close to 3 × 105 yr. In recent and more detailed models, numerous additional reactions are considered (Willacy and Millar, 1998), but these efforts have ...
25.4 Galaxies and the Universe
25.4 Galaxies and the Universe

... expansion occurred, hurling this material in all directions ...
Dark Matter in the Universe
Dark Matter in the Universe

... meters (81 miles) per second. As eager spectators, we must it. For every gram of glowing material we can detect, watch this encounter for a few decades to know if M31 will strike our galaxy or merely slide by. If they do collide, we will there may be tens of grams of dark matter out there. Currently ...
CH30 p798
CH30 p798

... nucleus. Heavier nuclei are bound more strongly than lighter nuclei. Except for a few nuclei, the binding energy per nucleon becomes more negative as the mass number, A, increases to a value of 56, which is that of iron, Fe. The most tightly bound nucleus is 56 26Fe; thus, nuclei become more stable ...
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Big Bang nucleosynthesis

In physical cosmology, Big Bang nucleosynthesis (abbreviated BBN, also known as primordial nucleosynthesis) refers to the production of nuclei other than those of the lightest isotope of hydrogen (hydrogen-1, 1H, having a single proton as a nucleus) during the early phases of the universe. Primordial nucleosynthesis is believed by most cosmologists to have taken place from 10 seconds to 20 minutes after the Big Bang, and is calculated to be responsible for the formation of most of the universe's helium as the isotope helium-4 (4He), along with small amounts of the hydrogen isotope deuterium (2H or D), the helium isotope helium-3 (3He), and a very small amount of the lithium isotope lithium-7 (7Li). In addition to these stable nuclei, two unstable or radioactive isotopes were also produced: the heavy hydrogen isotope tritium (3H or T); and the beryllium isotope beryllium-7 (7Be); but these unstable isotopes later decayed into 3He and 7Li, as above.Essentially all of the elements that are heavier than lithium and beryllium were created much later, by stellar nucleosynthesis in evolving and exploding stars.
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