论文标题
符合GW170817的纠正Einstein-Gauss-Bonnet通货膨胀
Rectifying Einstein-Gauss-Bonnet Inflation in View of GW170817
论文作者
论文摘要
在这项工作中，我们引入了一个新的理论框架，用于爱因斯坦 - 加斯 - 鲍尼特重力理论，这导致运动，功能简单，透明的运动，慢速索引和相应的观察指数特别优雅，功能简单和透明的重力方程。主要要求是爱因斯坦 - 加斯 - 邦网理论必须与GW170817事件兼容，因此重力波速度$ C_T^2 $是自然单位中的$ C_T^2 \ simeq 1 $。这个假设也是我们先前的工作中提出的，但是在这项工作中，我们将所有相关数量表示为标量场的功能。约束$ c_t^2 \ simeq 1 $限制标量高斯 - 骨网耦合函数$ξ（ϕ）$和标量电位$ v（ϕ）$的功能形式，该函数必须满足微分方程。但是，通过还假设缓慢滚动的条件成立，由此产生的运动方程和慢速索引获得了特别简单的形式，以及产生$ e $折叠数的关系为$ n = \ in = \ int_ {ϕ_i}^{ϕ_i}^{ϕ__f}^{ϕ__f}型号。正如证明的那样，我们提出的模型与观察数据兼容，并且还满足提取运动重力方程式过程中所做的所有假设。更有趣的是，我们还研究了附加条件$ξ'/ξ''\ ll 1 $的现象学含义，这是由于标量场演化和哈勃速率施加的缓慢滚动条件所激发的，在这种情况下，研究更容易。我们的方法在可行的爱因斯坦 - 加斯 - 鲍尼特重力理论中打开了一个新的窗口。
In this work we introduce a new theoretical framework for Einstein-Gauss-Bonnet theories of gravity, which results to particularly elegant, functionally simple and transparent gravitational equations of motion, slow-roll indices and the corresponding observational indices. The main requirement is that the Einstein-Gauss-Bonnet theory has to be compatible with the GW170817 event, so the gravitational wave speed $c_T^2$ is required to be $c_T^2\simeq 1$ in natural units. This assumption was also made in a previous work of ours, but in this work we express all the related quantities as functions of the scalar field. The constraint $c_T^2\simeq 1$ restricts the functional form of the scalar Gauss-Bonnet coupling function $ξ(ϕ)$ and of the scalar potential $V(ϕ)$, which must satisfy a differential equation. However, by also assuming that the slow-roll conditions hold true, the resulting equations of motion and the slow-roll indices acquire particularly simple forms, and also the relation that yields the $e$-foldings number is $N=\int_{ϕ_i}^{ϕ_f}ξ''/ξ'd ϕ$, a fact that enables us to perform particularly simple calculations in order to study the inflationary phenomenological implications of several models. As it proves, the models we presented are compatible with the observational data, and also satisfy all the assumptions made during the process of extracting the gravitational equations of motion. More interestingly, we also investigated the phenomenological implications of an additional condition $ξ'/ξ''\ll 1$, which is motivated by the slow-roll conditions that are imposed on the scalar field evolution and on the Hubble rate, in which case the study is easier. Our approach opens a new window in viable Einstein-Gauss-Bonnet theories of gravity.
