Do beam-plasma instabilities drain blazar pair beams before they radiate? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Do beam-plasma instabilities drain blazar pair beams before they radiate?
Plain
The electron-positron beams made by gamma rays in empty space might lose their energy to the thin intergalactic plasma before emitting gamma rays. If so, the missing gamma rays would not require magnetic fields at all.
Precise · changed · core
Revision 1: For TeV-blazar pair beams with Lorentz factors $\sim 1e6$ traversing void plasma with $n_e \sim 1e-7\,\mathrm{cm}^{-3}$ and $T \sim 1e4\,\mathrm{K}$, determine whether the nonlinear saturated growth of the electrostatic oblique instability drains beam energy faster than inverse-Compton cooling on the CMB. Answer yes or no from kinetic simulations or analytic theory that includes nonlinear Landau damping and plasma inhomogeneity.
Revision 2: For TeV-blazar pair beams with Lorentz factors $\sim 10^{6}$ traversing void plasma with $n_e \sim 10^{-7}\,\mathrm{cm}^{-3}$ and $T \sim 10^{4}\,\mathrm{K}$, determine whether the nonlinear saturated growth of the electrostatic oblique instability drains beam energy faster than inverse-Compton cooling on the CMB. Answer yes or no from kinetic simulations or analytic theory that includes nonlinear Landau damping and plasma inhomogeneity.
Settled by
Particle-in-cell simulations at realistic beam-to-plasma density ratios, extrapolated with a validated nonlinear theory.
Kind
well-posed
Answer type
yes-no
References
(empty)
Literature status
contested
Status note
2025 to 2026 cascade simulations including instability cooling find that the inferred field bounds depend on the assumed saturation parameters.
Posed since
2012

Decisions