We explore the consequences of a time-dependent inflaton equation-of-state (EoS) parameter in the context of the post-inflationary perturbative Boltzmann reheating. In particular, we numerically solve the perturbative coupled system of Boltzmann equations involving the inflaton energy density, the radiation energy density and the related entropy density and temperature of the produced particle thermal bath. We exploit reasonable Ansätze for the EoS and discuss the robustness of the Boltzmann system. We also comment on the possible microscopic origin related to a time-dependent inflaton potential, discussing the consequences on a preheating stage and the related (primordial) gravitational waves.

中文翻译：

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变膨胀状态方程和再加热

我们在暴胀后扰动玻尔兹曼再加热的背景下探索了与时间相关的暴胀状态方程 (EoS) 参数的后果。特别是，我们数值求解了涉及暴胀能量密度、辐射能量密度以及相关熵密度和产生的粒子热浴温度的玻尔兹曼方程的微扰耦合系统。我们为 EoS 开发了合理的 Ansätze，并讨论了玻尔兹曼系统的鲁棒性。我们还评论了与时间相关的暴胀势相关的可能微观起源，讨论了预热阶段和相关（原始）引力波的后果。