2021/07/31 by Abhijit B. Bendre, Kandaswamy Subramanian · 1 citation
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Electromotive force #Geomagnetism and Paleomagnetism Studies #Mechanics #Order (exchange) #Physics #Quantum mechanics #Solar and Space Plasma Dynamics #Stellar, planetary, and galactic studies #Turbulence #astro-ph.GA #physics.flu-dyn #physics.plasm-ph
paper · pdf · doi:10.1093/mnras/stac339
published in Monthly Notices of the Royal Astronomical Society 511(3), 4454-4463 (Oxford University Press) · 11 pages, 13 figures
openalex publication_date 2022/02/09 · arxiv created 2022/02/10 · arxiv updated 2022/02/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
ABSTRACT The generation of large-scale magnetic fields (\boldsymbol B) in astrophysical systems is driven by the mean turbulent electromotive force (\rm\boldsymbol \cal E ), the cross-correlation between local fluctuations of velocity and magnetic fields. This can depend non-locally on \boldsymbol B through a convolution kernel Kij. In a new approach to find Kij, we directly fit the time-series data of \rm\boldsymbol \cal E versus \boldsymbol B from a galactic dynamo simulation using singular value decomposition. We calculate the usual turbulent transport coefficients as moments of Kij, and show the importance of including non-locality over eddy length-scales to fully capture their amplitudes and that higher order corrections to the standard transport coefficients are small in this case.