The quintessence field coupled to the cosmic neutrino background (CNB) has been widely discussed as an alternative mechanism to address the coincidence problem. As it is well known, it is possible to extend such models to obtain quintessential inflation, that is, to incorporate inflationary stage as well. Taking an alternative route, one can start from the well established inflationary models and obtain successful quintessence models at the expense of coupling with the CNB. To Follow this route, we use a slightly reformulated model addressed in PRD95, 123521 (2017). This particular model assumes $\mathcal{Z}_2$ symmetry for both scalar field potential and coupling term, which then breaks down in course of the cosmological evolution. For our discussion, however, the $\mathcal{Z}_2$ symmetry of the potential is not mandatory the model to work. The conventional mechanism of particle production by the oscillating inflaton field (and their subsequent thermalization) remains operative. It is plain to see that the proposed construction can be easily applied for many successful models of inflation to incorporate dark energy at the expense of coupling with the CNB. We address the issue of neutrino nuggets from the quantum field theory point of view. Namely, these nuggets are considered as bound states caused basically by the Yukawa force, which arises in the framework of linear perturbation theory due to exchange of virtual quanta of quintessence field between the neutrinos.
Primordial black hole formation in inflationary $α$-attractor models
利用超共形暴胀$α$吸引子研究了原初黑洞的形成.一个暴胀子潜在的构造与高原状的区域，这带来了一个超慢滚区域的发病所需的曲率功率谱的增强发生。这是通过仔细微调电位中的参数来实现的。对于参数集，可观察到的膨胀量使得曲率扰动$\mathcal{P}_{\mathcal{R}}$在$\sim 10^{14}\text{Mpc}^{-1}$处达到峰值，从而在质量窗口$10^{16}\text{g}\leq M \leq 10^{18}\text{g}$中产生PBH。考虑到充气后的再加热期，以确定PBH的形成是否发生在这样的阶段。最后，计算了曲率扰动增强可能产生的二阶引力波谱。
Inflationary magnetogenesis from non-minimal coupling in large- and small-field potentials
Università di Camerino（卡梅里诺大学）；University at Albany-SUNY（奥尔巴尼州立大学（纽约州立大学））；INAF - Osservatorio Astronomico di Brera（意大利国家天体物理研究所布雷拉天文台）；Al-Farabi Kazakh National University（阿尔法拉比哈萨克国立大学）；Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Perugia（意大利国家核物理学院佩鲁吉亚分部）
The alternative scalar field dark sector of the Universe: Cosmological inflation, quintessence and ekpyrotic model in the framework of scalar-tensor cosmology
