We study the sensitivity of LiteBIRD and CMB-S4 to the reheating temperature and the inflaton coupling in three types of plateau-potential models of inflation, namely mutated hilltop inflation, radion gauge inflation, and α-attractor T models. We first find relations between model parameters and CMB observables in all models. We then perform Monte Carlo Markov Chain based forecasts to quantify the information gain on the reheating temperature, the inflaton coupling, and the scale of inflation that can be achieved with LiteBIRD and CMB-S4, assuming a fiducial tensor-to-scalar ratio r̅ ∼ 0.02 and neglecting foreground contamination of the B-mode polarization spectrum. We compare the results of the forecasts to those obtained from a recently proposed simple analytic method. We find that both LiteBIRD and CMB-S4 can simultaneously constrain the scale of inflation and the reheating temperature in all three types of models. They can for the first time obtain both an upper and lower bound on the latter, comprising the first ever measurement of the big bang temperature. In the mutated hilltop inflation and radion gauge inflation models this can be translated into a measurement of the inflaton coupling in parts of the parameter space. Constraining this microphysical parameter will help to understand how these models of inflation may be embedded into a more fundamental theory of particle physics.

中文翻译：

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LiteBIRD 和 CMB-S4 对通货膨胀高原模型中再加热的敏感性


我们研究了 LiteBIRD 和 CMB-S4 对再加热温度的敏感性以及三种暴胀平台势模型（即突变山顶暴胀、放射性规暴胀和 α-吸引子 T 模型）中的暴胀耦合。我们首先找到所有模型中模型参数和 CMB 可观测量之间的关系。然后，我们执行基于蒙特卡罗马尔可夫链的预测，以量化使用 LiteBIRD 和 CMB-S4 可以实现的再加热温度、暴胀耦合和暴胀规模的信息增益，假设基准张量与标量之比 r̅ ∼ 0.02 并忽略 B 模式偏振光谱的前景污染。我们将预测结果与最近提出的简单分析方法获得的结果进行比较。我们发现，LiteBIRD 和 CMB-S4 都可以同时约束所有三种模型中的膨胀规模和再加热温度。他们首次获得了后者的上限和下限，包括首次测量大爆炸温度。在突变的山顶暴胀和辐射规暴胀模型中，这可以转化为参数空间部分中暴胀耦合的测量。限制这个微观物理参数将有助于理解这些暴胀模型如何嵌入到更基本的粒子物理理论中。