论文标题
标量暗物质的初始条件
Initial conditions for the scalaron dark matter
论文作者
论文摘要
如果公制$ f（r）$重力的标量如果其质量在$ 4 \，\ text {mev} \ lyseSim m \ lyseSim 1 \，\ text {mev} $的范围内，则可能构成暗物质。我们概述了这种$ f（r）$重力理论最少与标准模型结合在一起。与基于标量字段的其他深色模型类似，该模型具有初始条件的问题。首先，要调整标量的初始条件，以产生观察到的暗物质量。其次，该领域的原始空间不均匀性应该足够小，因为它们会产生熵（或异性侵蚀）扰动，这些扰动受到观测的约束。我们在本文中考虑了这些问题。标量的初始条件大概是在通货膨胀阶段出现的。我们指出，由于通货膨胀期间的量子扩散，标量初始值的均匀部分在很大程度上是不可预测的。因此，要考虑到观察到的暗物质数量，必须诉诸于人类考虑。标量的原始空间不均匀性的观察性约束在通货膨胀的能量尺度上转化为上限，这恰好是低但不太限制的。
The scalaron of the metric $f(R)$ gravity can constitute dark matter if its mass is in the range $4\,\text{meV} \lesssim m \lesssim 1\,\text{MeV}$. We give an overview of such $f (R)$ gravity theory minimally coupled to the Standard Model. Similarly to other dark-matter models based on scalar fields, this model has the issue of initial conditions. Firstly, the initial conditions for the scalaron are to be tuned in order to produce the observed amount of dark matter. Secondly, the primordial spatial inhomogeneities in the field are to be sufficiently small because they generate entropy (or isocurvature) perturbations, which are constrained by observations. We consider these issues in the present paper. The initial conditions for the scalaron presumably emerge at the inflationary stage. We point out that the homogeneous part of the scalaron initial value is largely unpredictable because of quantum diffusion during inflation. Thus, to account for the observed amount of dark matter, one has to resort to anthropic considerations. Observational constraints on the primordial spatial inhomogeneity of the scalaron are translated into upper bounds on the energy scale of inflation, which happen to be low but not too restrictive.
