AI 中文总结
研究利用星系巡天搜索折叠原初非高斯性，考虑三种相关暴胀模型，开发数值管道计算其对星系功率谱多极矩和双谱单极矩的贡献，通过费舍尔预测表明星系双谱对折叠PNG约束能力强，其可探测性取决于折叠增强特性，数值管道具通用性。
AI 中文摘要
大规模结构通过原初非高斯性（PNG）为暴胀物理提供了有力探测手段：星系功率谱通过与尺度相关的偏差依赖于局域PNG，而星系双谱则敏感地依赖于等边和正交PNG。本文研究星系巡天能否探测折叠PNG，其形状在$k_1 + k_2 - k_3 \to 0$附近增强。考虑了三种具有折叠PNG的暴胀模型，分为截断调节情况（折叠增强区域有幂律宽度）和耗散调节情况（增强区域指数窄）。开发了数值管道来计算EFTofLSS中红移空间星系功率谱多极矩和双谱单极矩的相应PNG贡献。通过费舍尔预测表明，对折叠PNG的大部分约束能力来自星系双谱。对于截断调节模型，讨厌参数边缘化在大折叠增强时仅导致轻微信息损失，但一旦折叠区域比傅里叶空间分箱宽度窄，有限的分箱会降低约束。对于耗散调节模型，指数窄的折叠增强难以分辨，可观测信号来自模板的更广泛支持，导致分箱依赖性较弱但与等边模板重叠较大。结果表明折叠PNG是星系双谱分析的独特且有前景的目标，可探测性取决于折叠增强的宽度和形态。本文开发的数值管道具有通用性，可用于研究广泛的不可分离原初双谱。
英文摘要
Large-scale structure provides a powerful probe of inflationary physics through primordial non-Gaussianity (PNG): the galaxy power spectrum depends on local PNG through scale-dependent bias, while the galaxy bispectrum depends sensitively on both equilateral and orthogonal PNG. In this paper, we study whether galaxy surveys can also probe folded PNG, whose shape is enhanced near $k_1+k_2-k_3\rightarrow0$. We consider three inflationary models with folded PNG, including excited initial states, imaginary speeds of sound, and dissipative inflation. These models fall into two classes: cutoff-regulated cases in which the folded-enhanced region has a power-law width, and dissipation-regulated cases in which the enhanced region is exponentially narrow. We develop a numerical pipeline for computing the corresponding PNG contributions to the redshift-space galaxy power spectrum multipoles and bispectrum monopole within the EFTofLSS. Using Fisher forecasts, we show that most of the constraining power on folded PNG comes from the galaxy bispectrum. For the cutoff-regulated models, nuisance parameter marginalization causes only a mild loss of information at large folded enhancement, but finite Fourier-space binning degrades constraints once the folded region becomes narrower than the bin width. For the dissipation-regulated models, the exponentially narrow folded enhancement is hard to resolve and the observable signal instead comes from the broader support of the template, leading to weaker binning dependence but larger overlap with the equilateral template. Our results show that folded PNG is a distinctive and promising target for galaxy bispectrum analyses, and the detectability depends on the width and morphology of the folded enhancement. The numerical pipeline developed in this work is general and can be used to study a wide class of non-separable primordial bispectra.
Comments24 pages, 7 figures. Comments welcome!
