Statistics Seminar Series
Tuesday December 9, 4:10pm, MSB 1147 (Colloquium Room)
Speaker: Jessica Cisewski (Carnegie Mellon University)
Title: “Cosmology with Persistent Homology and the Lyman-alpha Forest”
Abstract: Data exhibiting complicated spatial structures are common in many areas of science (e.g. cosmology, biology), but can be difficult to analyze. Persistent homology offers a new way to represent, visualize, and interpret complex data by extracting topological features, which can be used to infer properties of the underlying structures. This work is motivated by the interest of cosmologists to visualize and model the very distant Universe using information from quasars. Light we observe from quasars has traveled through the intergalactic medium (IGM) to reach us, and leaves an imprint of some properties of the IGM on its spectrum, dubbed the Lyman-alpha forest. From this imprint, we can infer the density of neutral hydrogen along the line of sight to the quasar. The Sloan Digital Sky Survey Data Release 9 produced over 54,000 quasar spectra that can be used for analysis of the Lyman-alpha forest and, thus, aid cosmologists in further understanding the IGM along with revealing or corroborating other properties of the Universe.