发表机构
Institute of Astrophysics, Department of Physics and Astronomy, Universidad Andrés Bello; Department of Physics, University of Oxford（安第斯贝尔托大学天体物理研究所; 牛津大学物理系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究探讨演化暗能量下，采用特定非最小耦合标量-张量模型预测的引力波相关参数，与GWTC-5约束的一致性，发现宇宙学数据约束与该模型预测存在张力，且参数化模型存在隐式先验问题。
AI 中文摘要
与引力非最小耦合的标量场可成为宇宙加速膨胀的驱动源，这类非最小耦合（NMC）会产生非零的引力波（GW）摩擦函数α_M(z)，进而使从引力波源推断出的光度距离与其电磁对应体的光度距离产生偏差。我们采用一种与DESI高度吻合、能解释时变暗能量的特定NMC标量-张量模型，预测α_M(z)及预期的GW/电磁光度距离比D_L^GW/D_L^EM，并将其映射到两种常见参数化形式——c_M模型和(Ξ₀,n)模型。我们得到c_M = -0.5±0.2，Ξ₀ = 0.88±0.05，n = 3.2±0.3，两者均与GWTC-5约束在≤1σ水平上一致。这种一致性主要源于当前引力波数据的大不确定性，使得测量结果既与ΛCDM模型也与NMC模型相符。相比之下，基于宇宙学数据分析得到的暗能量约束，采用α_M(z)=c_MΩ_Λ(z)/Ω_Λ0的常见参数化标量-张量模型以及CPL参数化的状态方程w0wa，与NMC对c_M（w0wa）参数的预测存在2.2σ（3.6σ）的张力。我们证实，为避免宇宙学不稳定性，该参数化模型施加了强隐式先验，在暗能量为动力学形式时，与物理动机的标量-张量模型不兼容。
英文摘要
A scalar field non-minimally coupled to gravity can be the driver of cosmic acceleration. Such a non-minimal coupling (NMC) can produce a non-zero gravitational-wave (GW) friction function $α_M(z)$, which modifies the luminosity distance inferred from GW sources relative to its electromagnetic counterpart. We use a particular NMC scalar-tensor model, that explains time-varying dark energy in good alignment with DESI, to predict $α_M(z)$ and the expected GW/EM luminosity-distance ratio $D_L^{\rm GW}/D_L^{\rm EM}$, and map it onto two common parametrizations---the $c_M$ and the $(Ξ_0,n)$ models. We find $c_M = -0.5\pm 0.2$ and $Ξ_0 = 0.88\pm 0.05$, $n=3.2\pm 0.3$, both consistent with GWTC-5 constraints at the $\lesssim 1σ$ level. This consistency is mostly driven by current large uncertainties in GW data, which lead to measurements consistent with both $Λ$CDM and the NMC model. By contrast, the dark energy constraints derived from analyzing cosmological data, under the common parametric scalar-tensor model using $α_M(z)=c_MΩ_Λ(z)/Ω_{Λ0}$ and the CPL parametrized equation of state $w_0w_a$, are in $2.2σ$ ($3.6σ$) tension with the NMC predictions for the $c_M$ ($w_0w_a$) parameter. We confirm that, in order to avoid cosmological instabilities, this parametrized model imposes strong implicit priors that are incompatible with physically-motivated scalar-tensor models when dark energy is dynamical.
