We discuss tensor metric perturbations in a magnetic field around the homogeneous Juttner equilibrium of massless particles in an expanding universe. We solve the Liouville equation and derive the energy-momentum tensor up to linear terms in the metric and in the magnetic field.The term linear in the magnetic field is different from zero if the total charge of the primordial plasma is non-zero. We obtain an analytic formula for temperature fluctuations treating the tensor metric perturbations and the magnetic field as independent random variables. Assuming a cutoff on large momenta of the magnetic spectral function we show that the presence of the magnetic field can discriminate only low multipoles in the multipole expansion of temperature fluctuations. In such a case the term linear in the magnetic field can be more important than the quadratic one (corresponding to the fluctuations of the pure magnetic field).
Cosmological evolution of the cosmological plasma with interpartial scalar interaction. III. Model with the attraction of the like scalar charged particles
The complete relativistic kinetic model of violation of symmetry in isotopic expanding plasma and production of baryons in hot Universe. I. Exact model
The complete relativistic kinetic model of violation of symmetry in isotopic expanding plasma and production of baryons in hot Universe. II. Numerical model: X-boson distribution function
One-loop correction to primordial tensor modes during radiation era
Universität Leipzig（莱比锡大学）；Institute of Physics of the Czech Academy of Sciences（捷克科学院物理研究所）；Università di Pavia（帕维亚大学）；Istituto Nazionale di Fisica Nucleare（意大利国家核物理研究所）；Università di Trento（特伦托大学）
Constraining Primordial Black-Hole Bombs through Spectral Distortions of the Cosmic Microwave Background
研究了非蒸发原初黑洞超辐射不稳定性对宇宙微波背景谱的影响。在辐射主导的时代，PBH被大致均匀的宇宙等离子体包围，通过等离子体频率赋予光子有效质量。在这种情况下，旋转的PBH是不稳定的，通过众所周知的“黑洞炸弹”机制自发自旋下降。在线性水平下，光子密度被有效光子质量捕获，并且由于超辐射而随时间呈指数增长。当等离子体密度由于宇宙膨胀而下降时，PBH周围的相关能量被释放并在CMB中消散。我们评估了在红移范围10^3 < z < 2x10^6内CMB的光谱畸变。利用现有的COBE/FIRAS对CMB光谱畸变的限制，我们得到了在10^{-8}*Msun < M < 0.2*Msin的质量范围内与自旋PBH相关的暗物质的分数上限。对于最大自旋PBH，我们的限制比微透镜或其他方法得到的限制要严格得多。来自拟议的PIXIE任务的未来数据可以将我们的限制提高几个数量级。
