论文标题
在退化的高阶标量理论中具有宇宙微波背景的重力理论
Testing gravity theories with cosmic microwave background in the degenerate higher-order scalar-tensor theory
论文作者
论文摘要
我们研究了退化高阶标量（DHOST）理论的宇宙微波背景（CMB），以检验重力理论。这个理论框架包括一类广泛的暗能量模型，例如Horndeski理论及其作为某些限制的扩展，并且也可以恢复一般相对论。在这项研究中，为了通过CMB检验重力理论，我们在理论中制定了重力和物质的线性扰动及其有效描述，该参数是由时间依赖性有效田间理论（EFT）参数（$α_i$ $ $ $ $ $ $）（i = b，k，k，k，t，t，t，m，h，h，h，h，h，h，h，h，l）$ $β_i$ $ $ $ $ $ $ $ $ $ $ $ = 1,2,2,3）$。基于最终的DHOST框架，我们开发了一个数值代码来始终如一地求解Boltzmann方程。然后，我们表明，CMB温度各向异性，电子模式和镜头电位的角功率光谱作为演示，并发现表征DHOST理论$β_1$的参数提供了与其他eft参数相比的较大光谱修饰的参数。我们还显示了在特定模型的情况下，宇宙扩展以及EFT参数始终如一地确定的结果。
We study the cosmic microwave background (CMB) in the framework of the degenerate higher-order scalar-tensor (DHOST) theory to test gravity theories. This theoretical framework includes the wide class of dark energy models such as the Horndeski theory and its extensions as certain limits, and the general relativity can be also recovered. In this study, to test gravity theories with CMB, we formulate the linear perturbations of gravity and matter in the theory and their effective description parameterised by time-dependent effective field theory (EFT) parameters, $α_i$ $(i=B,K,T,M,H,L)$ and $β_i$ $(i=1,2,3)$. Based on the resultant DHOST framework, we develop a numerical code to solve Boltzmann equations consistently. We then show that the angular power spectra of the CMB temperature anisotropies, E-mode and lensing potential as a demonstration and find that the parameter characterising the DHOST theory, $β_1$, provides the larger modifications of the spectra, compared with other EFT parameters. We also show the results in the case of a specific model in which the cosmic expansion as well as the EFT parameters are consistently determined.
