Inflationary Magnetogenesis with Helical Coupling

We describe a simple scenario of inflationary magnetogenesis based on a helical coupling to electromagnetism. It allows the generation of helical magnetic fields with strength of order up to 10−7 Gs, when extrapolated to the current epoch, in a narrow spectral band centered at any physical wavenumber after the adjustment of model parameters. The additional constraints on magnetic fields arise from the considerations of baryogenesis and, possibly, from the Schwinger effect of the creation of charged particle-antiparticle pairs.

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Establishment of narrow spectral band model parameters database for gas high temperature radiation characteristics

Infrared and Laser Engineering ◽

10.3788/irla201746.0704001 ◽

2017 ◽

Vol 46 (7) ◽

pp. 704001

Author(s):

蔡红华 Cai Honghua ◽

聂万胜 Nie Wansheng ◽

吴睿 Wu Rui ◽

苏凌宇 Su Lingyu ◽

侯志勇 Hou Zhiyong

Keyword(s):

High Temperature ◽

Spectral Band ◽

Model Parameters ◽

Band Model ◽

Radiation Characteristics ◽

Narrow Spectral Band ◽

Temperature Radiation

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Comparative study of charged particle dynamics in time-stationary and time-varying spatially chaotic magnetic fields with sinusoidal spatiotemporal dependence

Chaos An Interdisciplinary Journal of Nonlinear Science ◽

10.1063/5.0042386 ◽

2021 ◽

Vol 31 (8) ◽

pp. 083113

Author(s):

Subha Samanta

Keyword(s):

Charged Particle ◽

Magnetic Fields ◽

Comparative Study ◽

Particle Dynamics ◽

Time Varying

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More about solar g modes

Astronomy and Astrophysics ◽

10.1051/0004-6361/201832626 ◽

2018 ◽

Vol 612 ◽

pp. L1 ◽

Cited By ~ 5

Author(s):

E. Fossat ◽

F. X. Schmider

Keyword(s):

Cross Correlation ◽

Previous Analysis ◽

Model Parameters ◽

Real Spectrum ◽

Space Observatory ◽

Correlation Peak ◽

Similar Frequency ◽

Precise Estimation ◽

The One ◽

Additional Constraints

Context. The detection of asymptotic solar g-mode parameters was the main goal of the GOLF instrument onboard the SOHO space observatory. This detection has recently been reported and has identified a rapid mean rotation of the solar core, with a one-week period, nearly four times faster than all the rest of the solar body, from the surface to the bottom of the radiative zone. Aim. We present here the detection of more g modes of higher degree, and a more precise estimation of all their parameters, which will have to be exploited as additional constraints in modeling the solar core. Methods. Having identified the period equidistance and the splitting of a large number of asymptotic g modes of degrees 1 and 2, we test a model of frequencies of these modes by a cross-correlation with the power spectrum from which they have been detected. It shows a high correlation peak at lag zero, showing that the model is hidden but present in the real spectrum. The model parameters can then be adjusted to optimize the position (at exactly zero lag) and the height of this correlation peak. The same method is then extended to the search for modes of degrees 3 and 4, which were not detected in the previous analysis.Results. g-mode parameters are optimally measured in similar-frequency bandwidths, ranging from 7 to 8 μHz at one end and all close to 30 μHz at the other end, for the degrees 1 to 4. They include the four asymptotic period equidistances, the slight departure from equidistance of the detected periods for l = 1 and l = 2, the measured amplitudes, functions of the degree and the tesseral order, and the splittings that will possibly constrain the estimated sharpness of the transition between the one-week mean rotation of the core and the almost four-week rotation of the radiative envelope. The g-mode periods themselves are crucial inputs in the solar core structure helioseismic investigation.

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Schwinger effect in an instanton background with electric and magnetic fields via holography

Modern Physics Letters A ◽

10.1142/s0217732318501444 ◽

2018 ◽

Vol 33 (25) ◽

pp. 1850144

Author(s):

Maryam Gholizadeh Arashti ◽

Majid Dehghani

Keyword(s):

Magnetic Field ◽

Magnetic Fields ◽

Production Rate ◽

Pair Creation ◽

Zero Temperature ◽

Expectation Value ◽

Background Magnetic Field ◽

Electric And Magnetic Fields ◽

Schwinger Effect ◽

Horizon Limit

The Schwinger effect in the presence of instantons and background magnetic field was considered to study the dependence of critical electric field on instanton density and magnetic field using AdS/CFT conjecture. The gravity side is the near horizon limit of D3[Formula: see text]D(−[Formula: see text]1) background with electric and magnetic fields on the brane. Our approach is based on the potential analysis for particle–antiparticle pair at zero and finite temperatures, where the zero temperature case is a semi-confining theory. We find that presence of instantons suppresses the pair creation effect, similar to a background magnetic field. Then, the production rate will be obtained numerically using the expectation value of circular Wilson loop. The obtained production rate in a magnetic field is in agreement with previous results.

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