The Effect of the Brans-Dicke Cosmology on Solar Evolution and Neutrino Fluxes

1969 ◽  
Vol 155 ◽  
pp. 135 ◽  
Author(s):  
G. Shaviv ◽  
J. N. Bahcall
Keyword(s):  
Solar Evolution ◽  
Neutrino Fluxes

scholarly journals The impact of composition choices on solar evolution: age, helio- and asteroseismology, and neutrinos

2020 ◽  
Vol 498 (2) ◽  
pp. 1992-2000
Author(s):  
Diogo Capelo ◽  
Ilídio Lopes
Keyword(s):  
The Sun ◽  
Fundamental Parameters ◽  
Element Abundances ◽  
Solar Evolution ◽  
Oxygen Cycle ◽  
Potential Impact ◽  
Red Giant ◽  
Neutrino Fluxes ◽  
Neutrino Experiments ◽  
The Impact

ABSTRACT The Sun is the most studied and well-known star, and as such, solar fundamental parameters are often used to bridge gaps in the knowledge of other stars, when these are required for modelling. However, the two most powerful and precise independent methodologies currently available to infer the internal solar structure are in disagreement. We aim to show the potential impact of composition choices in the overall evolution of a star, using the Sun as example. To this effect, we create two Standard Solar Models and a comparison model using different combinations of metallicity and relative element abundances and compare evolutionary, helioseismic, and neutrino-related properties for each. We report differences in age for models calibrated to the same point on the HR diagram, in red giant branch, of more than 1 Gyr, and found that the current precision level of asteroseismic measurements is enough to differentiate these models, which would exhibit differences in period spacing of 1.30–2.58 per cent. Additionally, we show that the measurement of neutrino fluxes from the carbon–nitrogen–oxygen cycle with a precision of around 17 per cent, which could be achieved by the next generation of solar neutrino experiments, could help resolve the stellar abundance problem.

scholarly journals Updated solar neutrino fluxes with new heavy element abundances

2020 ◽  
Vol 19 ◽  
pp. 66
Author(s):  
G. I. Karathanou ◽  
V. Tsikoudi ◽  
T. S. Kosmas
Keyword(s):  
Solar Neutrino ◽  
Heavy Element ◽  
Convection Zone ◽  
Reaction Rates ◽  
Extensive Study ◽  
Element Abundances ◽  
Solar Structure ◽  
Solar Evolution ◽  
Microphysical Parameters ◽  
Neutrino Fluxes

In the present work we carry out an extensive study of the solar structure and solar evolution through the use of the TYCHO 6.92 code, which includes a variety of programs and subroutines. In this code we incorporate the most updated microphysical parameters such as screening, recent experimental measurements of the astrophysical factors-S (LUNA), several updated, recently measured, heavy element abundances, etc., and created new models describing crucial phenomena of the solar structure and solar evolution. We used this code to calculate and update nuclear reaction rates, solar neutrino fluxes, solar quantities which characterize the internal solar structure such as temperature, pressure, density, luminosity, heavy element abundances (4He, 12C, 14N, 16O, etc.) as well as sound speed profile and depth of the convection zone.

scholarly journals Mass-loss varying luminosity and its implication to the solar evolution

2019 ◽  
Vol 15 (S356) ◽  
pp. 403-404
Author(s):  
Negessa Tilahun Shukure ◽  
Solomon Belay Tessema ◽  
Endalkachew Mengistu
Keyword(s):  
Standard Model ◽  
Mass Loss ◽  
Main Sequence ◽  
The Sun ◽  
Solar Mass ◽  
Solar Luminosity ◽  
Solar Evolution

AbstractSeveral models of the solar luminosity, , in the evolutionary timescale, have been computed as a function of time. However, the solar mass-loss, , is one of the drivers of variation in this timescale. The purpose of this study is to model mass-loss varying solar luminosity, , and to predict the luminosity variation before it leaves the main sequence. We numerically computed the up to 4.9 Gyrs from now. We used the solution to compute the modeled . We then validated our model with the current solar standard model (SSM). The shows consistency up to 8 Gyrs. At about 8.85 Gyrs, the Sun loses 28% of its mass and its luminosity increased to 2.2. The model suggests that the total main sequence lifetime is nearly 9 Gyrs. The model explains well the stage at which the Sun exhausts its central supply of hydrogen and when it will be ready to leave the main sequence. It may also explain the fate of the Sun by making some improvements in comparison to previous models.

scholarly journals Sensitivity of direct detection experiments to neutrino magnetic dipole moments

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
D. Aristizabal Sierra ◽  
R. Branada ◽  
O. G. Miranda ◽  
G. Sanchez Garcia
Keyword(s):  
Dark Matter ◽  
Magnetic Dipole ◽  
Direct Detection ◽  
Dipole Moments ◽  
Nuclear Recoil ◽  
Active Volume ◽  
Electron Recoil ◽  
Flux Measurements ◽  
Neutrino Fluxes ◽  
One Year

Abstract With large active volume sizes dark matter direct detection experiments are sensitive to solar neutrino fluxes. Nuclear recoil signals are induced by 8B neutrinos, while electron recoils are mainly generated by the pp flux. Measurements of both processes offer an opportunity to test neutrino properties at low thresholds with fairly low backgrounds. In this paper we study the sensitivity of these experiments to neutrino magnetic dipole moments assuming 1, 10 and 40 tonne active volumes (representative of XENON1T, XENONnT and DARWIN), 0.3 keV and 1 keV thresholds. We show that with nuclear recoil measurements alone a 40 tonne detector could be as competitive as Borexino, TEXONO and GEMMA, with sensitivities of order 8.0 × 10−11μB at the 90% CL after one year of data taking. Electron recoil measurements will increase sensitivities way below these values allowing to test regions not excluded by astrophysical arguments. Using electron recoil data and depending on performance, the same detector will be able to explore values down to 4.0 × 10−12μB at the 90% CL in one year of data taking. By assuming a 200-tonne liquid xenon detector operating during 10 years, we conclude that sensitivities in this type of detectors will be of order 10−12μB. Reducing statistical uncertainties may enable improving sensitivities below these values.

scholarly journals Solar structure and evolution

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Jørgen Christensen-Dalsgaard
Keyword(s):  
Solar Surface ◽  
Solar Neutrinos ◽  
Solar Interior ◽  
Stellar Structure ◽  
The Sun ◽  
Physical Processes ◽  
Solar Evolution ◽  
Internal Properties ◽  
Atmospheric Phenomena

AbstractThe Sun provides a critical benchmark for the general study of stellar structure and evolution. Also, knowledge about the internal properties of the Sun is important for the understanding of solar atmospheric phenomena, including the solar magnetic cycle. Here I provide a brief overview of the theory of stellar structure and evolution, including the physical processes and parameters that are involved. This is followed by a discussion of solar evolution, extending from the birth to the latest stages. As a background for the interpretation of observations related to the solar interior I provide a rather extensive analysis of the sensitivity of solar models to the assumptions underlying their calculation. I then discuss the detailed information about the solar interior that has become available through helioseismic investigations and the detection of solar neutrinos, with further constraints provided by the observed abundances of the lightest elements. Revisions in the determination of the solar surface abundances have led to increased discrepancies, discussed in some detail, between the observational inferences and solar models. I finally briefly address the relation of the Sun to other similar stars and the prospects for asteroseismic investigations of stellar structure and evolution.

Neutrino oscillations and the atmospheric neutrino fluxes

1984 ◽  
Vol 30 (1) ◽  
pp. 80-88 ◽  
Author(s):  
G. V. Dass ◽  
K. V. L. Sarma
Keyword(s):  
Neutrino Oscillations ◽  
Atmospheric Neutrino ◽  
Neutrino Fluxes

Giant horizontal air showers. Implications for AGN neutrino fluxes

1992 ◽  
Vol 289 (1-2) ◽  
pp. 184-188 ◽  
Author(s):  
F. Halzen ◽  
E. Zas
Keyword(s):  
Air Showers ◽  
Neutrino Fluxes

scholarly journals Optimization of neutrino fluxes for future long baseline neutrino oscillation experiments

2016 ◽  
Vol 273-275 ◽  
pp. 2681-2683
Author(s):  
M. Calviani ◽  
S. di Luise ◽  
V. Galymov ◽  
P. Velten
Keyword(s):  
Neutrino Oscillation ◽  
Long Baseline ◽  
Neutrino Fluxes
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