A large bulk flow, which is in tension with the Lambda Cold Dark Matter ($Λ$CDM) cosmological model, has been observed. In this paper, we provide a physically plausible explanation of this bulk flow, based on the assumption that some fraction of the observed dipole in the cosmic microwave background is due to an intrinsic fluctuation, so that the subtraction of the observed dipole leads to a mismatch between the cosmic microwave background (CMB) defined rest frame and the matter rest frame. We investigate a model that takes into account the relative velocity (hereafter the tilted velocity) between the two frames, and develop a Bayesian statistic to explore the likelihood of this tilted velocity.
By studying various independent peculiar velocity catalogs, we find that: (1) the magnitude of the tilted velocity $u$ is around 400 km/s, and its direction is close to what is found from previous bulk flow analyses; for most catalogs analysed, u=0 is excluded at about the $2.5 σ$ level;(2) constraints on the magnitude of the tilted velocity can result in constraints on the duration of inflation, due to the fact that inflation can neither be too long (no dipole effect) nor too short (very large dipole effect); (3) Under the assumption of a super-horizon isocurvature fluctuation, the constraints on the tilted velocity require that inflation lasts at least 6 e-folds longer (at the 95% confidence interval) than that required to solve the horizon problem. This opens a new window for testing inflation and models of the early Universe from observations of large scale structure.
Constraining Primordial Power Asymmetry from Galaxy Clustering and Peculiar Velocity Information
Kyoto University（京都大学）；Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）；Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo（东京大学前沿科学高等研究院宇宙物理数学卡弗里研究所（WPI））；Korea Institute for Advanced Study（韩国高等科学研究院）；Academia Sinica Institute of Astronomy and Astrophysics (ASIAA)（中央研究院天文及天文物理学研究所）；Onomichi City University（尾道市立大学）
Constraining the optical depth of galaxies and velocity bias with cross-correlation between kinetic Sunyaev-Zeldovich effect and peculiar velocity field
Constraining cosmological simulations with peculiar velocities: a forward-modeling approach
Aix Marseille Université（艾克斯-马赛大学）；CNRS/IN2P3, CPPM（法国国家科学研究中心/法国国家粒子物理研究所，粒子与核物理中心）；Leibniz-Institut für Astrophysik Potsdam（波茨坦莱布尼茨天体物理研究所）；Racah Institute of Physics, Hebrew University（希伯来大学雷卡物理学研究所）；Institut de Recherche sur les Lois Fondamentales de l’Univers, CEA, Universite’ Paris-Saclay（CEA巴黎萨克雷大学基础宇宙定律研究所）；University of Oxford（牛津大学）；Institute for Astronomy, University of Hawaii（夏威夷大学天文学研究所）
Approximations for the divergence of the local large-scale structure velocity field and its implications for Tilted Cosmology
Instituto de Física y Astronomía, Universidad de Valparaíso（瓦尔帕莱索大学物理与天文学研究所）；Centro científico tecnológico de Valparaíso, Universidad Federico Santa María（弗雷德里科·圣玛丽亚大学瓦尔帕莱索科技中心）
Using SPTpol, Planck 2015, and non-CMB data to constrain tilted spatially-flat and untilted non-flat $Λ$CDM, XCDM, and $ϕ$CDM dark energy inflation cosmologies
Using the tilted flat-$Λ$CDM and the untilted non-flat $Λ$CDM inflation models to measure cosmological parameters from a compilation of observational data
Probing the primordial universe with gravitational waves detectors
太初引力波（GW）的频谱，特别是它的倾斜度$n_T$，携带着有关太初宇宙的重要信息。结合最近的aLIGO和Planck 2015 + BK 14数据，我们发现电流极限是$n_T=0.016^{+0.614}_{-0.989}$在95% C. L。我们还估计了爱因斯坦望远镜和LISA对约束$n_T$的影响。此外，基于宇宙学扰动的有效场论，我们还尝试用相应的观测数据对产生蓝倾GWs谱（$n_T>0$）的一些早期宇宙模型进行了讨论。
Constraining Cosmological Parameters From Statistical Superluminal Effects Without a Distance Ladder
Research Unit in Scientific Culture and Mediation - CERIST（科学文化与调解研究单位-CERIST）；Laboratoire de Physique Mathématique et Subatomique (LPMS)（数学与亚原子物理实验室(LPMS)）；University of Constantine 1（君士坦丁第一大学）
