Tohfa Hurum Maksora, Bird Simeon, Ho Ming-Feng, Qezlou Mahdi, Fernandez Martin
Department of Physics and Astronomy, <a href="https://ror.org/03nawhv43">University of California Riverside</a>, Riverside, California 92521, USA.
Department of Astronomy, <a href="https://ror.org/00cvxb145">University of Washington</a>, Seattle, Washington 98195, USA.
Phys Rev Lett. 2024 Jun 7;132(23):231002. doi: 10.1103/PhysRevLett.132.231002.
We make forecasts for the constraining power of the 1D wavelet scattering transform when used with a Lyman-α forest cosmology survey. Using mock simulations and a Fisher matrix, we show that there is considerable cosmological information in the scattering transform coefficients not captured by the flux power spectrum. We estimate mock covariance matrices assuming uncorrelated Gaussian pixel noise for each quasar at a level drawn from a simple log-normal model. The extra information comes from a smaller estimated covariance in the first-order wavelet power and from second-order wavelet coefficients that probe non-Gaussian information in the forest. Forecast constraints on cosmological parameters from the wavelet scattering transform are more than an order of magnitude tighter than for the power spectrum, shrinking a 4D parameter space by a factor of 10^{6}. Should these improvements be realized with the Dark Energy Spectroscopic Instrument, inflationary running would be constrained to test common inflationary models predicting α_{s}=-6×10^{-4} and neutrino mass constraints would be improved enough for a 5-σ detection of the minimal neutrino mass.
我们对一维小波散射变换与莱曼-α森林宇宙学勘测结合使用时的约束能力进行了预测。通过模拟和费舍尔矩阵，我们表明散射变换系数中存在大量未被流量功率谱捕获的宇宙学信息。我们假设每个类星体的像素噪声为不相关的高斯噪声，并根据一个简单的对数正态模型确定其水平，以此来估计模拟协方差矩阵。额外的信息来自于一阶小波功率中较小的估计协方差以及探测森林中非高斯信息的二阶小波系数。来自小波散射变换对宇宙学参数的预测约束比功率谱的约束要严格一个数量级以上，将一个四维参数空间缩小了10^6倍。如果暗能量光谱仪能够实现这些改进，暴胀跑动将被限制以检验预测α_s = -6×10^-4的常见暴胀模型，并且中微子质量约束将得到足够的改善，从而能够5σ探测到最小中微子质量。
