时间：6月19日（周四）下午15：00-16：00

地点：勤园20-518

报告摘要：

If a sector other than inflaton survives in the late universe, its quantum fluctuation generically brings isocurvature modes. The typical case is the complex scalar with spontaneous symmetry breaking, with the remaining U(1) global symmetry and the associated massless goldstone boson. The goldstone mode can be recognized as the QCD axion or axion-like particle (ALP) and form cold dark matter via the misalignment mechanism. We found a whole new suite of cosmological observables for cold dark matter isocurvature, which could help test the presence of axions, as well as its coupling to the inflaton and other heavy spectator fields during inflation such as the radial mode of the Peccei-Quinn field. They include correlated clock signals in the curvature and isocurvature spectra, and mixed cosmological-collider non-Gaussianities involving both curvature and isocurvature fluctuations with shapes and running unconstrained by the current data analyses. We will also briefly mention further developments in progress

报告人简介：

李凌风，2013年在北京大学取得物理和化学的学士学位。2018年在加利福尼亚大学戴维斯分校获得理论高能物理学博士学位。随后，他在香港科技大学和布朗大学担任博士后研究员。他的主要研究方向为标准模型的精确测试和新物理探索，其研究也涵盖粒子物理学和宇宙学。