发表机构
Inner Mongolia Normal University; Qingdao University of Technology（内蒙古师范大学; 青岛理工大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究探讨暖暴胀中Yukawa相互作用产生的费米子对原初扰动的影响，发现热声传播和强耦合可放大标量扰动并抑制张标比，为粒子产生提供新机制。
AI 中文摘要
我们研究了在暴胀子场与狄拉克费米子之间存在Yukawa相互作用的暖暴胀场景中，费米子的产生及其宇宙学后果。将产生的费米子视为热化的相对论性流体，我们推导了包含耗散效应和热涨落的耦合扰动方程。通过格林函数方法求解所得系统，我们识别出热噪声、热声传播和高阶散射过程对标量扰动的不同贡献。我们表明，费米子涨落的声音传播在相对论性区域变得显著，在该区域引力吸引与泡利简并压之间的竞争使得集体费米子模式能够影响原初谱。此外，我们计算了费米子数密度和声速，揭示强Yukawa相互作用增强了非绝热费米子产生并修改了费米子浴的热力学性质。我们计算了源项标量和张量扰动，表明费米子产生可以显著放大原初涨落，特别是在强耦合区域。由于标量扰动比张量模式获得更有效的增强，张标比相对于标准单场暖暴胀预测被抑制。我们的结果表明，热化费米子提供了一种修改原初扰动的额外机制，并为粒子产生在暖暴胀宇宙学中的作用提供了新见解。
英文摘要
We investigate fermion production and its cosmological consequences in a warm inflationary scenario with a Yukawa interaction between the inflaton field and Dirac fermions. Treating the produced fermions as a thermalized relativistic fluid, we derive the coupled perturbation equations incorporating dissipative effects and thermal fluctuations. By solving the resulting system through Green's function methods, we identify distinct contributions from thermal noise, thermal-acoustic propagation, and higher-order scattering processes to the scalar perturbations. We show that acoustic propagation of fermionic fluctuations becomes significant in the relativistic regime, where the competition between gravitational attraction and Pauli degeneracy pressure allows collective fermionic modes to influence the primordial spectrum. Furthermore, we calculate the fermion number density and acoustic velocity, revealing that strong Yukawa interactions enhance non-adiabatic fermion production and modify the thermodynamic properties of the fermion bath. The sourced scalar and tensor perturbations are calculated, indicating that fermion production can substantially amplify primordial fluctuations, particularly in the strong-coupling regime. Since scalar perturbations receive more efficient enhancement than tensor modes, the tensor-to-scalar ratio is suppressed relative to the standard single-field warm inflation prediction. Our results show that thermalized fermions provide an additional mechanism for modifying primordial perturbations and offer new insights into the role of particle production in warm inflationary cosmology.
