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Sufficient and necessary conditions for collective neutrino instability: Fast, slow, and mixed

Basudeb Dasgupta* and Dwaipayan Mukherjee†

  • *Contact author: bdasgupta@theory.tifr.res.in
  • †Contact author: dwaipayan.mukherjee@tifr.res.in
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Phys. Rev. D 112, 123049 – Published 29 December, 2025

DOI: https://doi.org/10.1103/bqkr-rcwk

Abstract

Collective neutrino oscillations exhibit instabilities that induce appreciable flavor conversion, with crucial astrophysical implications. While the importance of initial phase-space distributions is well established, a general instability criterion for distributions dependent on both energy and emission angle has been lacking. We identify and analyze the sufficient (and necessary) conditions for a generic collective neutrino flavor instability.

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Phys. Rev. D 112, 123049– Published 29 December, 2025
  • Received 16 June 2025
  • Revised 25 November 2025
  • Accepted 2 December 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3.

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