Baryon Acoustic Oscillations (BAOs) in the early Universe are predicted to leave an as yet undetected signature on the relative clustering of total mass versus luminous matter. This signature, a modulation of the relative large-scale clustering of baryons and dark matter, offers a new angle to compare the large scale distribution of light versus mass. A detection of this effect would provide an important confirmation of the standard cosmological paradigm and constrain alternatives to dark matter as well as non-standard fluctuations such as Compensated Isocurvature Perturbations (CIPs). The first attempt to measure this effect in the SDSS-III BOSS Data Release 10 CMASS sample remained inconclusive but allowed to develop a method, which we detail here and use to conduct the second observational search. When using the same model as in our previous study and including CIPs in the model, the DR12 data are consistent with a null-detection, a result in tension with the strong evidence previously measured with the DR10 data. This tension remains when we use a more realistic model taking into account our knowledge of the survey flux limit, as the data then privilege a zero effect. In the absence of CIPs, we obtain a null detection consistent with both the absence of the effect and the amplitude predicted in previous theoretical studies. This shows the necessity of more accurate data in order to prove or disprove the theoretical predictions.
翻译:早期宇宙中的巴里翁声波振荡(BAOs)预计将在总质量相对于光质的相对组群中留下一个尚未察觉到的标志。 这个标志是调制相对大比例的阵列和暗物质,为比较光与质量的大规模分布提供了一个新的角度。 检测这一效果将大大地证实标准宇宙范式,并限制暗物质和非标准波动的替代物,如补偿性Isocurationaturburbations(CIPs) 。 在SDSS-III BOSS数据发布10 CMASS样本中测量这一效应的首次尝试仍然没有结果,但能够开发出一种方法,我们在此进行详细介绍并用于进行第二次观测搜索。当使用与我们先前研究相同的模型,包括模型中的CIPs,DR12数据与无效检测相一致,导致与先前与DR10数据测量的强证据相矛盾。 当我们使用更符合现实的模型来测量这一效果时,这种紧张状态仍然存在,因为我们既了解了我们没有准确的预测性数据,又了解了对零位数据的准确性研究的影响。