scholarly journals Influence of a quasi-molecular mechanism of recombination on the formation of hydrogen in the early Universe

2020 ◽  
Vol 501 (1) ◽  
pp. 1160-1167
Author(s):  
Tamaz Kereselidze ◽  
Irakli Noselidze ◽  
John F Ogilvie
Keyword(s):  
Hydrogen Atom ◽  
Binding Energy ◽  
Molecular Mechanism ◽  
Early Universe ◽  
Ground State ◽  
Atomic Hydrogen ◽  
Molecular Approach ◽  
Evolution Of The Universe ◽  
Radiative Transitions ◽  
The Universe

ABSTRACT In the framework of a quasi-molecular approach, the formation of hydrogen atom in the pre-recombination period of evolution of the Universe is analysed quantitatively. Calculations in an adiabatic multilevel representation enable estimates of probabilities of radiative transitions. The quasi-molecular mechanism of recombination allows the formation of hydrogen molecular ion, ${\mathrm{ H}_2}^+$, in its ground state. The probability of this process is comparable with the probability of the creation of atomic hydrogen. The participation of a second proton in the recombination increases the binding energy of an electron and decreases the rate of recombination of hydrogen.

Formation of hydrogen in the early universe: quasi-molecular mechanism of recombination

2019 ◽  
Vol 488 (2) ◽  
pp. 2093-2098
Author(s):  
Tamaz Kereselidze ◽  
Irakli Noselidze ◽  
John F Ogilvie
Keyword(s):  
Hydrogen Atom ◽  
Molecular Mechanism ◽  
Early Universe ◽  
Atomic Hydrogen ◽  
Radiative Transition

ABSTRACT The recombination of an electron and a proton is assumed to occur in the presence of another proton, which participates in the process. The system of colliding particles is considered as a quasi-molecule temporarily formed during a collision. This model is employed to treat the formation of atomic hydrogen in the pre-recombination period of evolution of the early universe. According to a quasi-molecular mechanism of recombination, two processes are responsible for the formation of hydrogen in the early universe – a radiative transition of an electron to an excited repulsive state of $\mathrm{ H}_2^ + $ with a subsequent dissociation into a hydrogen atom and a proton, and a radiative transition of an electron to an excited attractive state of $\mathrm{ H}_2^ + $ with a subsequent cascade downward to a low-lying repulsive state. The participation of the nearest neighbouring proton in the process is shown to decrease the probability of recombination on an isolated proton.

The Very Early Universe

1988 ◽  
Vol 20 (1) ◽  
pp. 656-658
Author(s):  
K. Sato
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Early Universe ◽  
Early Stage ◽  
Topological Defects ◽  
Evolution Of The Universe ◽  
Grand Unified Theories ◽  
Unified Theories ◽  
The Universe

In recent years, the research on the very early universe has shown quite remarkable developments. As is well known, this development was brought about by the introduction of the Grand Unified Theories (GUTs) into cosmology. These theories have not only enabled us to trace the evolution of the Universe back to the very early stage at temperatures of 1016 GeV or higher, but also introduced various new aspects into cosmology, such as baryogenesis, phase transitions and topological defects (monopoles, etc.). In particular, inflation, which grew out of the study of GUT phase transition, is the most important and fascinating outcome.

scholarly journals Electron capture in slow collisions of O6+ions with atomic hydrogen

2019 ◽  
Vol 625 ◽  
pp. A29
Author(s):  
Xiaohe Lin ◽  
Yong Wu ◽  
J. G. Wang ◽  
Bin Shao ◽  
R. K. Janev
Keyword(s):  
Electron Capture ◽  
Cross Sections ◽  
Ground State ◽  
Atomic Hydrogen ◽  
Theoretical Data ◽  
Rate Coefficients ◽  
Hydrogen Atoms ◽  
Close Coupling ◽  
Radiative Transitions ◽  
Reaction Channels

Aims. Electron capture in collisions of highly charged O6+ions with ground-state hydrogen atoms is a very important process in solar wind X-ray studies.Methods. In the present study, the full quantum-mechanical molecular-orbital close-coupling method is employed to study electron capture reactions in collisions of O6+ion with ground-state atomic hydrogen in the energy region from 10−4keV u−1to 5 keV u−1. The ab initio multi-reference single- and double-excitation configuration interaction (MRD-CI) method is used to calculate the potential and coupling data used in the QMOCC calculations.Results. Total and state-selective cross sections for the dominant and subdominant reaction channels are calculated and compared with the available experimental and theoretical data. The branching ratios for Lithium-like O5+excited ions are used to calculate the contribution of cascade radiative transitions fromn = 5 levels to the population of 4l states. From the calculated cross sections, reaction rate coefficients are obtained for temperatures between 1000 and 1 × 109K and compared with other calculations.

Deviations of R2 cosmology from the Einstein’s General Relativity

2020 ◽  
Vol 35 (36) ◽  
pp. 2044026
Author(s):  
E. V. Arbuzova
Keyword(s):  
General Relativity ◽  
Early Universe ◽  
Significant Influence ◽  
Particle Production ◽  
Cosmological Evolution ◽  
Evolution Of The Universe ◽  
History Of ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Einstein’S General Relativity

The cosmological history of the universe in the [Formula: see text] gravity is studied starting from the “very beginning” up to the present time. The primordial inflationary expansion of the universe is considered and it is shown that the gravitational particle production by the oscillating curvature, [Formula: see text], led to a consistent transition to the Friedmann cosmology, but the cosmological evolution in the early universe strongly differed from the standard one. It is shown that the effects of gravitational production of particles had a significant influence on the evolution of the universe.

Dynamical Evolution of the Universe in the Quark-Hadron Phase Transition and Nugget Formation

2005 ◽  
Vol 201 ◽  
pp. 461-462
Author(s):  
Ashok. Goyal ◽  
Deepak. Chandra
Keyword(s):  
Phase Transition ◽  
Early Universe ◽  
Dynamical Evolution ◽  
First Order ◽  
Evolution Of The Universe ◽  
Hadron Phase ◽  
First Order Phase Transition ◽  
Nugget Formation ◽  
First Order Phase ◽  
The Universe

We study the dynamics of first-order phase transition in the early Universe when it was 10 −50μs old with quarks and gluons condensing into hadrons. We look at the evolution of the Universe in small as well as large super cooling scenario.

scholarly journals Observational Determinations of the Proton to Electron Mass Ratio in the Early Universe

2009 ◽  
Vol 5 (H15) ◽  
pp. 319-319
Author(s):  
Rodger I. Thompson
Keyword(s):  
Early Universe ◽  
Electron Mass ◽  
Mass Ratio ◽  
Fundamental Physical Constants ◽  
Molecular Absorption ◽  
Lyman Alpha ◽  
Evolution Of The Universe ◽  
The Universe ◽  
Fundamental Physical

AbstractThe values of the fundamental physical constants determine the nature of our universe from the height of mountains on earth to the evolution of the universe over its history. One of these constants is μ = MP/Me the ratio of the proton to electron mass. Astronomical observations provide a determination of this ratio in the early universe through observations of molecular absorption and emission lines in distant objects. Observations of molecular hydrogen in distant damped Lyman Alpha clouds provide a measurement of μ at a time when the universe was only 20% of its present age. To date there is no evidence for a change in μ at the level of 1 part in 105. This limit produces an observational constraint on quintessence theories for the evolution of the universe and Super Symmetric theories of elementary particles.

STUDIES OF Λ(1405) WITH K-MESIC ATOMS

2011 ◽  
Vol 26 (03n04) ◽  
pp. 402-407
Author(s):  
SŁAWOMIR WYCECH
Keyword(s):  
Binding Energy ◽  
Atomic Hydrogen ◽  
Scattering Amplitude ◽  
Absorptive Part ◽  
Experimental Tests ◽  
P Wave ◽  
Subthreshold Region ◽  
Radiative Transitions ◽  
Mesic Atom

Experimental tests of the Λ(1405) properties are suggested. These could reflect the position and shape of this state in the [Formula: see text] channel. The first test consists in precise determinations of the level widths in the highest accessible K -mesic atom states. One needs to study the dependence of these widths on the binding energy of the valence protons in the involved nuclei. The second test consists in the measurement of radiative transitions from the P-wave atomic hydrogen levels to the Λ(1405) state. In both cases one can study the absorptive part of [Formula: see text] scattering amplitude in the subthreshold region.

scholarly journals The Thermal History of the Universe and the Spectrum of Relic Radiation

1974 ◽  
Vol 63 ◽  
pp. 167-173
Author(s):  
R. A. Sunyaev
Keyword(s):  
Energy Release ◽  
Early Universe ◽  
Thermal History ◽  
Energy Production ◽  
Cosmological Models ◽  
Clear Picture ◽  
Evolution Of The Universe ◽  
Strong Turbulence ◽  
History Of ◽  
The Universe

Many of the cosmological models currently under discussion and theories of the origin of galaxies which involve antimatter, strong turbulence and so on result in significant energy release during the evolution of the Universe. It is evident that significant energy production should lead to distortions of the spectrum of the relic radiation. The absence of noticeable deviations from the Planckian spectrum enables us to set limits to the energy release in the early Universe (102 < z< 108). But in order to have a clear picture of possible distortions, let us first review the idealized situation.

scholarly journals Fine Structure Constant, Domain Walls, and Generalized Uncertainty Principle in the Universe

2011 ◽  
Vol 2011 ◽  
pp. 1-12
Author(s):  
Luigi Tedesco
Keyword(s):  
Fine Structure ◽  
Hydrogen Atom ◽  
Domain Wall ◽  
Uncertainty Principle ◽  
Ground State ◽  
Domain Walls ◽  
Generalized Uncertainty Principle ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
The Universe

We study the corrections to the fine structure constant from the generalized uncertainty principle in the spacetime of a domain wall. We also calculate the corrections to the standard formula to the energy of the electron in the hydrogen atom to the ground state, in the case of spacetime of a domain wall and generalized uncertainty principle. The results generalize the cases known in literature.

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