标题： 非局部方法对宇宙常数问题中的宇宙加速研究 显示英文标题

标题： Cosmic Acceleration in the Nonlocal Approach to the Cosmological Constant Problem

摘要： 我们最近构建了一个明确的局域表述，用以处理宇宙常数问题的非定域方法，该表述能够同时考虑物质和引力场的量子效应。 在此表述中，已经明确表明即使存在引力圈效应，有效的宇宙常数也是辐射稳定的。 由于我们自然地需要在原始作用量中加入 $R^2$ 项及其对应的整体作用量，我们利用这种表述来解释开放宇宙（具有无限时空体积）的晚期加速膨胀。 我们将看到，当存在于 $R^2$ 引力中的“标量子”——作为额外的标量场——具有大约 ${\cal{O}}(1 meV)$ 数量级的微小质量时，我们可以一致地解释当前宇宙常数的数值。 显示英文摘要

摘要： We have recently constructed a manifestly local formulation of a nonlocal approach to the cosmological constant problem which can treat with quantum effects from both matter and gravitational fields. In this formulation, it has been explicitly shown that the effective cosmological constant is radiatively stable even in the presence of the gravitational loop effects. Since we are naturally led to add the $R^2$ term and the corresponding topological action to an original action, we make use of this formulation to account for the late-time acceleration of expansion of the universe in case of the open universes with infinite space-time volume. We will see that when the "scalaron", which exists in the $R^2$ gravity as an extra scalar field, has a tiny mass of the order of magnitude ${\cal{O}}(1 meV)$, we can explain the current value of the cosmological constant in a consistent manner.