Accounting for Baryons in Dark Energy Constraints: From DES to LSST

该计划的目标是利用模拟来理解由构成正常物质的粒子（称为“重子”）引起的弱引力透镜效应分布的修正；引力透镜是一种过程，在这个过程中，大量的物质使来自更远的物体的光弯曲，这些物体位于物质分布之外。这些模拟将减少下一代使用弱透镜研究导致宇宙加速膨胀的“暗能量”现象的系统误差。更广泛的影响是实质性的，包括本科生和研究生的培训，以及公众宣传。Zentner博士将在阿勒格尼天文台进行公开演讲，在卡内基科学中心布尔学院进行教育活动，组织匹兹堡大学的天文学推广计划，并在公立学校教师的继续教育活动中进行演讲。该计划解决的问题是，所有弱透镜调查都是在小尺度上进行的，重子效应在暗能量研究的解释中变得很重要，并包括精心计划的步骤来处理这些效应。一个关键的优势是使用多种方法来模拟重子效应：通过修改密度分布来参数化重子效应；采用盲法分析不同重子效应的模拟；集群扩展方法；和拉格朗日方法。

The goal of this program is to use simulations to understand corrections to the distribution of weak gravitational lensing effects caused by the particles that make up normal matter (known as "baryons"); gravitational lensing is the process in which large amounts of matter bend the light coming from more distant objects, located beyond the matter distributions. These simulations would reduce systematic errors for next-generation studies of the "dark energy" phenomenon that causes the accelerating expansion of the universe that use weak lensing. Broader impacts are substantial and include training of undergraduate and graduate students, as well as public outreach. Dr. Zentner will give public lectures at the Allegheny Observatory, conduct educational events at the Carnegie Science Center Buhl Academy, organize the University of Pittsburgh's Astronomy Outreach Program, and lecture at continuing education events for public school teachers. The program addresses the issue that all weak lensing surveys probe small scales where baryonic effects become important in the interpretation of dark energy studies, and includes carefully planned steps to deal with these effects. A key strength is the use of multiple approaches to model the effects of baryons: parameterizing baryonic effects by modifying density profiles; using blind analyses of simulations with different baryonic effects; cluster expansion methods; and Lagrangian methods.