论文标题
CMB对DHOST理论的约束
CMB constraints on DHOST theories
论文作者
论文摘要
我们使用Planck 2018的可能性对退化的高阶标量（DHOST）理论放大了约束。 In our previous paper, we developed a Boltzmann solver incorporating the effective field theory parameterised by the six time-dependent functions, $α_i$ $(i={\rm B},{\rm K},{\rm T},{\rm M},{\rm H})$ and $β_1$, which can describe the DHOST theories.使用Markov-Chain Monte-Carlo方法与我们的Boltzmann求解器一起，我们发现模型参数的可行参数区域表征了DHOST理论和其他标准宇宙学参数。首先，我们考虑使用$α_ {\ rm k} =ω_ {\ rm de}（t）/ω_ {\ rm de}（t_0）$，$α__{\ rm b} =α_ {\ rm t} =α_ { H}=0$ and $β_1=β_{1,0}Ω_{\rm DE}(t)/Ω_{\rm DE}(t_0)$ in the $Λ$CDM background where $t_0$ is the present time and obtain $β_{1,0}=0.032_{-0.016}^{+0.013}$ （68 \％C.L.）。接下来，我们重点介绍$ \ Mathcal {l} _ {\ rm dhost} = x + c_3x \ boxC/λ^3 +（m _ {\ rm pl}^2/2 + c_4x^2/λ^2/λ^6）R + 48c_4^2x^2x^2x^2/（m _ = \ rm） pl}^2λ^{12}+2c_4λ^6x^2）ϕ^μϕ_ {μρ} ϕ^{ρν} ϕ_ν $带有$ x：= \ partial_μϕ \ partial_μϕ \ partial^μϕ $和两个正常常数参数，$ c_3 $和$ c_3 $和$ c_3 $和$ c_4 $。在此模型中，我们始终如一地对待背景和扰动，并获得$ C_3 = 1.59^{+0.26} _ { - 0.28} $，以及上限上的$ C_4 $，$ C_4 <0.0088 $（68 \％c.l.）。
We put constraints on the degenerate higher-order scalar-tensor (DHOST) theories using the Planck 2018 likelihoods. In our previous paper, we developed a Boltzmann solver incorporating the effective field theory parameterised by the six time-dependent functions, $α_i$ $(i={\rm B},{\rm K},{\rm T},{\rm M},{\rm H})$ and $β_1$, which can describe the DHOST theories. Using the Markov-Chain Monte-Carlo method with our Boltzmann solver, we find the viable parameter region of the model parameters characterising the DHOST theories and the other standard cosmological parameters. First, we consider a simple model with $α_{\rm K} = Ω_{\rm DE}(t)/Ω_{\rm DE}(t_0)$, $α_{\rm B}=α_{\rm T}=α_{\rm M}=α_{\rm H}=0$ and $β_1=β_{1,0}Ω_{\rm DE}(t)/Ω_{\rm DE}(t_0)$ in the $Λ$CDM background where $t_0$ is the present time and obtain $β_{1,0}=0.032_{-0.016}^{+0.013}$ (68\% c.l.). Next, we focus on another theory given by $\mathcal{L}_{\rm DHOST} = X + c_3X\Boxϕ/Λ^3+ (M_{\rm pl}^2/2+c_4X^2/Λ^6)R + 48c_4^2X^2/(M_{\rm pl}^2Λ^{12}+2c_4Λ^6X^2)ϕ^μϕ_{μρ}ϕ^{ρν}ϕ_ν$ with $X:=\partial_μϕ\partial^μϕ$ and two positive constant parameters, $c_3$ and $c_4$. In this model, we consistently treat the background and the perturbations, and obtain $c_3 = 1.59^{+0.26}_{-0.28}$ and the upper bound on $c_4$, $c_4<0.0088$ (68\% c.l.).
