Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Letter
  • Open Access

Decay law of magnetic turbulence with helicity balanced by chiral fermions

Axel Brandenburg1,2,3,4, Kohei Kamada5, and Jennifer Schober6

  • 1Nordita, KTH Royal Institute of Technology and Stockholm University, 10691 Stockholm, Sweden
  • 2The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, 10691 Stockholm, Sweden
  • 3School of Natural Sciences and Medicine, Ilia State University, 0194 Tbilisi, Georgia
  • 4McWilliams Center for Cosmology and Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
  • 5Research Center for the Early Universe (RESCEU), Graduate School of Science, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
  • 6Institute of Physics, Laboratory of Astrophysics, École Polytechnique Fédérale de Lausanne (EPFL), 1290 Sauverny, Switzerland

Phys. Rev. Research 5, L022028 – Published 11 May, 2023

DOI: https://doi.org/10.1103/PhysRevResearch.5.L022028

Abstract

In plasmas composed of massless electrically charged fermions, chirality can be interchanged with magnetic helicity while preserving the total chirality through the quantum chiral anomaly. The decay of turbulent energy in plasmas such as those in the early Universe and compact stars is usually controlled by certain conservation laws. In the case of zero total chirality, when the magnetic helicity density balances with the appropriately scaled chiral chemical potential to zero, the total chirality no longer determines the decay. We propose that in such a case, an adaptation to the Hosking integral, which is conserved in nonhelical magnetically dominated turbulence, controls the decay in turbulence with helicity balanced by chiral fermions. We show, using a high resolution numerical simulation, that this is indeed the case. The magnetic energy density decays and the correlation length increases with time just like in nonhelical turbulence with vanishing chiral chemical potential. But here, the magnetic helicity density is nearly maximum and shows a scaling with time t proportional to t−2/3. This is unrelated to the t−2/3 decay of magnetic energy in fully helical magnetic turbulence. The modulus of the chiral chemical potential decays in the same fashion. This is much slower than the exponential decay previously expected in theories of asymmetric baryon production from the hypermagnetic helicity decay after axion inflation.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (41)

  1. L. Woltjer, A theorem on force-free magnetic fields, Proc. Natl. Acad. Sci. 44, 489 (1958).
  2. J. B. Taylor, Relaxation of Toroidal Plasma and Generation of Reverse Magnetic Fields, Phys. Rev. Lett. 33, 1139 (1974).
  3. A. Brandenburg and K. Subramanian, Astrophysical magnetic fields and nonlinear dynamo theory, Phys. Rep. 417, 1 (2005).
  4. D. N. Hosking and A. A. Schekochihin, Reconnection-Controlled Decay of Magnetohydrodynamic Turbulence and the Role of Invariants, Phys. Rev. X 11, 041005 (2021).
  5. A. A. Schekochihin, MHD turbulence: A biased review, J. Plasma Phys. 88, 155880501 (2022).
  6. H. Zhou, R. Sharma, and A. Brandenburg, Scaling of the Hosking integral in decaying magnetically dominated turbulence, J. Plasma Phys. 88, 905880602 (2022).
  7. A. Boyarsky, J. Fröhlich, and O. Ruchayskiy, Self-Consistent Evolution of Magnetic Fields and Chiral Asymmetry in the Early Universe, Phys. Rev. Lett. 108, 031301 (2012).
  8. I. Rogachevskii, O. Ruchayskiy, A. Boyarsky, J. Fröhlich, N. Kleeorin, A. Brandenburg, and J. Schober, Laminar and turbulent dynamos in chiral magnetohydrodynamics. I. Theory, Astrophys. J. 846, 153 (2017).
  9. S. L. Adler, Axial vector vertex in spinor electrodynamics, Phys. Rev. 177, 2426 (1969).
  10. J. S. Bell and R. Jackiw, A PCAC puzzle: π0→γγ in the σ model, Nuovo Cimento A 60, 47 (1969).
  11. M. Joyce and M. Shaposhnikov, Primordial Magnetic Fields, Right Electrons, and the Abelian Anomaly, Phys. Rev. Lett. 79, 1193 (1997).
  12. Y. Akamatsu and N. Yamamoto, Chiral Plasma Instabilities, Phys. Rev. Lett. 111, 052002 (2013).
  13. K. Kamada, Return of grand unified theory baryogenesis: Source of helical hypermagnetic fields for the baryon asymmetry of the universe, Phys. Rev. D 97, 103506 (2018).
  14. V. Domcke, K. Kamada, K. Mukaida, K. Schmitz, and M. Yamada, A new constraint on primordial lepton flavour asymmetries, arXiv:2208.03237.
  15. R. T. Co, V. Domcke, and K. Harigaya, Baryogenesis from decaying magnetic helicity in axiogenesis, arXiv:2211.12517.
  16. Y. Hirono, D. E. Kharzeev, and Y. Yin, Self-similar inverse cascade of magnetic helicity driven by the chiral anomaly, Phys. Rev. D 92, 125031 (2015).
  17. J. Schober, T. Fujita, and R. Durrer, Generation of chiral asymmetry via helical magnetic fields, Phys. Rev. D 101, 103028 (2020).
  18. V. Domcke and K. Mukaida, Gauge field and fermion production during axion inflation, J. Cosmol. Astropart. Phys. 11 (2018) 020.
  19. V. Domcke, B. von Harling, E. Morgante, and K. Mukaida, Baryogenesis from axion inflation, J. Cosmol. Astropart. Phys. 10 (2019) 032.
  20. V. Domcke, K. Kamada, K. Mukaida, K. Schmitz, and M. Yamada, Wash-in leptogenesis after axion inflation, J. High. Energy Phys. 01 (2023) 053.
  21. M. Giovannini and M. E. Shaposhnikov, Primordial hypermagnetic fields and triangle anomaly, Phys. Rev. D 57, 2186 (1998).
  22. M. Giovannini and M. E. Shaposhnikov, Primordial Magnetic Fields, Anomalous Matter-Antimatter Fluctuations, and Big Bang Nucleosynthesis, Phys. Rev. Lett. 80, 22 (1998).
  23. K. Kamada and A. J. Long, Evolution of the baryon asymmetry through the electroweak crossover in the presence of a helical magnetic field, Phys. Rev. D 94, 123509 (2016).
  24. K. Kamada, N. Yamamoto, and D.-L. Yang, Chiral effects in astrophysics and cosmology, Prog. Part. Nucl. Phys. 129, 104016 (2023).
  25. A. Brandenburg, J. Schober, I. Rogachevskii, T. Kahniashvili, A. Boyarsky, J. Fröhlich, O. Ruchayskiy, and N. Kleeorin, The turbulent chiral magnetic cascade in the early universe, Astrophys. J. 845, L21 (2017).
  26. A. Brandenburg, Y. He, T. Kahniashvili, M. Rheinhardt, and J. Schober, Relic gravitational waves from the chiral magnetic effect, Astrophys. J. 911, 110 (2021).
  27. A. Brandenburg, T. Kahniashvili, S. Mandal, A. R. Pol, A. G. Tevzadze, and T. Vachaspati, Evolution of hydromagnetic turbulence from the electroweak phase transition, Phys. Rev. D 96, 123528 (2017).
  28. R. Durrer and C. Caprini, Primordial magnetic fields and causality, J. Cosmol. Astropart. Phys. 11 (2003) 010.
  29. Pencil Code Collaboration, A. Brandenburg, A. Johansen, P. Bourdin, W. Dobler, W. Lyra, M. Rheinhardt, S. Bingert, N. Haugen, A. Mee, F. Gent, N. Babkovskaia, C.-C. Yang, T. Heinemann, B. Dintrans, D. Mitra, S. Candelaresi, J. Warnecke, P. Käpylä, A. Schreiber et al., The Pencil Code, a modular MPI code for partial differential equations and particles: Multipurpose and multiuser-maintained, J. Open Source Softw. 6, 2807 (2021).
  30. J. Schober, I. Rogachevskii, A. Brandenburg, A. Boyarsky, J. Fröhlich, O. Ruchayskiy, and N. Kleeorin, Laminar and turbulent dynamos in chiral magnetohydrodynamics. II. Simulations, Astrophys. J. 858, 124 (2018).
  31. J. Schober, A. Brandenburg, and I. Rogachevskii, Chiral fermion asymmetry in high-energy plasma simulations, Geophys. Astrophys. Fluid Dyn. 114, 106 (2020).
  32. A. Brandenburg, Hosking integral in nonhelical Hall cascade, J. Plasma Phys. 89, 175890101 (2023).
  33. A. Brandenburg and T. Kahniashvili, Classes of Hydrodynamic and Magnetohydrodynamic Turbulent Decay, Phys. Rev. Lett. 118, 055102 (2017).
  34. P. Olesen, Inverse cascades and primordial magnetic fields, Phys. Lett. B 398, 321 (1997).
  35. See also the discussion in Ref. [41] for weak magnetic field with zero magnetic helicity, where selfsimilarity is not assumed.
  36. T. Kahniashvili, A. G. Tevzadze, A. Brandenburg, and A. Neronov, Evolution of primordial magnetic fields from phase transitions, Phys. Rev. D 87, 083007 (2013).
  37. A. Brandenburg, K. Kamada, K. Mukaida, K. Schmitz, and J. Schober, Chiral magnetohydrodynamics with zero total chirality, arXiv:2304.06612.
  38. L. Del Zanna and N. Bucciantini, Covariant and 3 + 1 equations for dynamo-chiral general relativistic magnetohydrodynamics, Mon. Not. R. Astron. Soc. 479, 657 (2018).
  39. Y. Masada, K. Kotake, T. Takiwaki, and N. Yamamoto, Chiral magnetohydrodynamic turbulence in core-collapse supernovae, Phys. Rev. D 98, 083018 (2018).
  40. M. Dvornikov, V. B. Semikoz, and D. D. Sokoloff, Generation of strong magnetic fields in a nascent neutron star accounting for the chiral magnetic effect, Phys. Rev. D 101, 083009 (2020).
  41. F. Uchida, M. Fujiwara, K. Kamada, and J. Yokoyama, New description of the scaling evolution of the cosmological magneto-hydrodynamic system, arXiv:2212.14355.

Outline

Information

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation