scholarly journals Addendum to “Update on neutrino mixing in the early universe”

2003 ◽  
Vol 67 (12) ◽  
Author(s):  
P. Di Bari
Keyword(s):  
Early Universe ◽  
Neutrino Mixing

The early universe

1989 ◽  
Vol 159 (10) ◽  
pp. 393
Author(s):  
Ya.A. Smorodinskii
Keyword(s):  
Early Universe

scholarly journals VIBRATIONAL LEVEL POPULATION OF H 2 AND H + 2 IN THE EARLY UNIVERSE

2011 ◽  
Vol 193 (1) ◽  
pp. 7 ◽  
Author(s):  
Carla M. Coppola ◽  
Savino Longo ◽  
Mario Capitelli ◽  
Francesco Palla ◽  
Daniele Galli
Keyword(s):  
Early Universe ◽  
Vibrational Level ◽  
Level Population

scholarly journals IMPLICATIONS OF A QUANTUM MECHANICAL TREATMENT OF THE UNIVERSE

1998 ◽  
Vol 13 (05) ◽  
pp. 347-351 ◽  
Author(s):  
MURAT ÖZER
Keyword(s):  
Quantum Mechanics ◽  
Wave Packet ◽  
Early Universe ◽  
Mechanical Treatment ◽  
Correspondence Principle ◽  
Scale Factor ◽  
Quantum Mechanical ◽  
Quantum Mechanical Treatment ◽  
The Standard Model ◽  
The Universe

We attempt to treat the very early Universe according to quantum mechanics. Identifying the scale factor of the Universe with the width of the wave packet associated with it, we show that there cannot be an initial singularity and that the Universe expands. Invoking the correspondence principle, we obtain the scale factor of the Universe and demonstrate that the causality problem of the standard model is solved.

scholarly journals Electroweak axion string and superconductivity

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Yoshihiko Abe ◽  
Yu Hamada ◽  
Koichi Yoshioka
Keyword(s):  
Electric Current ◽  
Early Universe ◽  
Parameter Space ◽  
Cosmic String ◽  
Topological Charge ◽  
Attractive Force ◽  
Electroweak Scale ◽  
Large Current

Abstract We study the axion strings with the electroweak gauge flux in the DFSZ axion model and show that these strings, called the electroweak axion strings, can exhibit superconductivity without fermionic zeromodes. We construct three types of electroweak axion string solutions. Among them, the string with W-flux can be lightest in some parameter space, which leads to a stable superconducting cosmic string. We also show that a large electric current can flow along the string due to the Peccei-Quinn scale much higher than the electroweak scale. This large current induces a net attractive force between the axion strings with the same topological charge, which opens a novel possibility that the axion strings form Y-junctions in the early universe.

scholarly journals Current and future neutrino oscillation constraints on leptonic unitarity

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Sebastian A. R. Ellis ◽  
Kevin J. Kelly ◽  
Shirley Weishi Li
Keyword(s):  
Precise Measurement ◽  
Sterile Neutrino ◽  
Current Knowledge ◽  
Unknown Origin ◽  
Neutrino Masses ◽  
Matrix Elements ◽  
Neutrino Mixing ◽  
Next Generation ◽  
Active Neutrino ◽  
Mixing Matrix

Abstract The unitarity of the lepton mixing matrix is a critical assumption underlying the standard neutrino-mixing paradigm. However, many models seeking to explain the as-yet-unknown origin of neutrino masses predict deviations from unitarity in the mixing of the active neutrino states. Motivated by the prospect that future experiments may provide a precise measurement of the lepton mixing matrix, we revisit current constraints on unitarity violation from oscillation measurements and project how next-generation experiments will improve our current knowledge. With the next-generation data, the normalizations of all rows and columns of the lepton mixing matrix will be constrained to ≲10% precision, with the e-row best measured at ≲1% and the τ-row worst measured at ∼10% precision. The measurements of the mixing matrix elements themselves will be improved on average by a factor of 3. We highlight the complementarity of DUNE, T2HK, JUNO, and IceCube Upgrade for these improvements, as well as the importance of ντ appearance measurements and sterile neutrino searches for tests of leptonic unitarity.

scholarly journals Dark matter freeze-in from semi-production

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Andrzej Hryczuk ◽  
Maxim Laletin
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Cross Section ◽  
Thermal Equilibrium ◽  
Indirect Detection ◽  
Production Mechanism ◽  
Number Density ◽  
Matter Production ◽  
Relic Density ◽  
Standard Formalism

Abstract We study a novel dark matter production mechanism based on the freeze-in through semi-production, i.e. the inverse semi-annihilation processes. A peculiar feature of this scenario is that the production rate is suppressed by a small initial abundance of dark matter and consequently creating the observed abundance requires much larger coupling values than for the usual freeze-in. We provide a concrete example model exhibiting such production mechanism and study it in detail, extending the standard formalism to include the evolution of dark matter temperature alongside its number density and discuss the importance of this improved treatment. Finally, we confront the relic density constraint with the limits and prospects for the dark matter indirect detection searches. We show that, even if it was never in full thermal equilibrium in the early Universe, dark matter could, nevertheless, have strong enough present-day annihilation cross section to lead to observable signals.

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