适用于Vainshtein屏蔽Horndeski引力的高效单圈EFTofLSS框架
An efficient one-loop EFTofLSS framework for Vainshtein-screened Horndeski gravity
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中文总结 AI 辅助
本研究扩展了PyBird框架，开发适用于Vainshtein屏蔽Horndeski引力的高效单圈EFTofLSS方法，结合多观测数据约束修正引力参数，验证了其在大尺度结构分析中的适用性。
中文摘要 AI 辅助
我们对PyBird进行扩展，以用于修正引力模型的单圈大尺度结构分析。我们实现了对准静态、Vainshtein屏蔽的光速Horndeski模型（采用EFTofDE和协变形式）以及nDGP模型的支持，并将格林函数方法替换为直接常微分方程（ODE）方法，用于计算进入微扰核的精确时变函数。新实现提升了计算效率，同时保持了与标准方法的数值一致性，我们针对α_i∝Ω_DE参数化方案，将得到的单圈物质功率谱与N体模拟结果进行了验证。我们应用该框架，结合Planck CMB、BOSS全形和DESI DR2 BAO数据，对α_i∝a³和α_i∝Ω_DE参数化方案进行约束，发现全形信息显著收紧了约束范围。我们进一步展示了立方伽利略子和nDGP模型的处理流程，证明其适用性超出唯象振幅参数化方案，可用于协变修正引力理论。最后，我们评估了爱因斯坦-德西特近似的影响，发现以适度的计算成本即可保留精确的时变特性，这对未来的大尺度结构观测调查可能具有重要意义。
英文摘要
We present an extension of \texttt{PyBird} for one-loop large-scale structure analyses of modified gravity models. We implement support for quasi-static, Vainshtein-screened luminal Horndeski models (in EFTofDE and covariant formalisms) and nDGP, and replace the Green's function approach with a direct ODE method for computing the exact time-dependent functions entering the perturbation kernels. The new implementation improves computational efficiency while maintaining numerical consistency with the standard approach, and we validate the resulting one-loop matter power spectrum against $N$-body simulations for the $α_i\proptoΩ_{\rm DE}$ parametrization. We apply this framework to constrain the $α_i \propto a^3$ and $α_i \propto Ω_{\rm DE}$ parametrizations using Planck CMB, BOSS full-shape, and DESI DR2 BAO data, finding that full-shape information significantly tightens the constraints. We further showcase the pipeline for the cubic Galileon and nDGP models, demonstrating its applicability beyond the phenomenological amplitude parametrizations to covariant modified-gravity theories. Finally, we assess the impact of the Einstein--de Sitter approximation and find that exact time dependence can be retained at modest computational cost, which may become relevant for future large-scale structure surveys.
