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arXiv 2406.01475astro-ph.COgr-qc
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来自脉冲星计时阵列的暖暴胀新限制

New limits on warm inflation from pulsar timing arrays

Rocco D'Agostino, Matteo Califano

AI总结:

本研究通过分析暴胀后标量诱导引力波的演化,结合NANOGrav的脉冲星计时阵列观测数据,对弱暖暴胀模型的自由参数给出新约束,并利用贝叶斯推断对比了不同暴胀势场景的统计表现。

摘要:

本文研究暴胀后宇宙中由标量诱导产生的引力波(GWs),以推导暖暴胀的新限制。我们专门考察了辐射主导时期产生的标量扰动引发的原初引力波演化。为此,我们采用慢滚近似下的弱暖暴胀机制,假设耗散系数与辐射浴温度线性相关。随后,我们推导了暴胀场在混沌势和指数势情形下的曲率功率谱与标量谱指数的解析表达式。接着,我们将引力波遗迹能量密度的理论预测,与NANOGrav合作组近期通过脉冲星计时阵列测量探测到的随机引力波背景信号进行比对,由此得到了所研究暴胀模型自由参数的数值约束。最后,我们通过贝叶斯推断方法开展模型选择分析,以衡量不同理论场景的统计表现。

英文摘要:

In this paper, we investigate scalar-induced gravitational waves (GWs) generated in the post-inflationary universe to infer new limits on warm inflation. We specifically examine the evolution of primordial GWs by scalar perturbations produced during the radiation-dominated epoch. For this purpose, we assume a weak regime of warm inflation under the slow-roll approximation, with a dissipation coefficient linearly dependent on the temperature of the radiation bath. We then derive analytical expressions for the curvature power spectrum and the scalar index, in the cases of chaotic and exponential potentials of the inflationary field. Subsequently, we compare the theoretical predictions regarding the relic energy density of GWs with the stochastic GW background signal recently detected by the NANOGrav collaboration through the use of pulsar timing array measurements. In so doing, we obtain numerical constraints on the free parameters of the inflationary models under study. Finally, we conduct a model selection analysis through the Bayesian inference method to measure the statistical performance of the different theoretical scenarios.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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