论文标题
远距离相互作用的暗物质引起的天体物理血浆不稳定性
Astrophysical Plasma Instabilities induced by Long-Range Interacting Dark Matter
论文作者
论文摘要
如果将暗物质（DM）毫无用处或深色电荷，则集体等离子体过程可能会在直接粒子碰撞上占主导地位。等离子流的不稳定性可以将DM的动量与反流式的重子或其他DM相结合，并导致反流体彼此休息，就像天体物理系统中的无碰撞冲击一样。虽然当DM被毫米时，在感兴趣的宇宙学情况下，静电等离子体不稳定性通过Landau阻尼高度抑制，但诸如微生等电磁不稳定性可以使Momenta稍微降低，并假设线性不稳定性以Baryonic等离子体的典型方式饱和。我们发现，预混合宇宙中DM的流传输比集体过程更强烈地影响，从而验证了先前的约束。但是，考虑到$ [q_χ/m_χ] \ gtrsim 10^{-12} -10^{ - 11} $，在$ [q_χ/m_χ的$ [q_χ/m_χ] $中，$ [q_χ/m_χ] \ gtrsim 10^{ - q_χ/m_χ] $是d d ott ot d d d otto的，如果考虑$ [q_χ/m_χ] \ gtrsim 10^{ - 12} -10^{ - 11} $，在$ [q__q_χ/m_χ] $是d d ott ot vot的情况下。在黑暗$ u（1）$充电的情况下，芯片增长率甚至更快，可能排除$ [q_χ/m_χ] \ gtrsim 10^{ - 14} $在子弹群集系统中与以前的工作一致。以前的Millicharged DM（MDM）最强的限制是考虑到银河系磁盘的旋转而产生的。我们表明，血浆不稳定性或纠结的背景磁场可能导致DM的扩散繁殖，从而削弱这些旋转限制。因此，等离子体不稳定性可能会在大部分毫米上放置一些最严格的约束，而我们的结果证实了先前的深度势能限制，对深色负责的参数空间。
If dark matter (DM) is millicharged or darkly charged, collective plasma processes may dominate momentum exchange over direct particle collisions. Plasma streaming instabilities can couple the momentum of the DM to counter-streaming baryons or other DM and result in the counter-streaming fluids coming to rest with each other, just as happens for baryonic collisionless shocks in astrophysical systems. While electrostatic plasma instabilities are highly suppressed by Landau damping when DM is millicharged, in the cosmological situations of interest, electromagnetic instabilities such as the Weibel can couple momenta, assuming that the linear instability saturates in the manner typically found for baryonic plasmas. We find that the streaming of DM in the pre-Recombination universe is affected more strongly by direct collisions than collective processes, validating previous constraints. However, when considering magnetized Weibel and Firehose instabilities, the properties of the Bullet Cluster merger are likely to be substantially altered if $[q_χ/m_χ] \gtrsim 10^{-12}-10^{-11}$, where $[q_χ/m_χ]$ is the charge-to-mass ratio of the DM relative to that of the proton. The Weibel growth rates are even faster in the case of a dark-$U(1)$ charge, potentially ruling out $[q_χ/m_χ] \gtrsim 10^{-14}$ in the Bullet Cluster system, in agreement with previous work. The strongest previous limits on millicharged DM (mDM) arise from considering the spin-down of galactic disks. We show that plasma instabilities or tangled background magnetic fields could lead to diffusive propagation of the DM, weakening these spin-down limits. Thus, plasma instabilities may place some of the most stringent constraints over much of the millicharged, and our results corroborate previous extremely stringent potential constraints on the dark-charged parameter space.
