Dr. Zhilei Xu
Precision Cosmology : from CMB to 21cm
Location: 1080 Physics Research Building, Smith Seminar Room
Faculty Host: Amy Connolly
Abstract: Over the past decades, observations of the cosmic microwave background (CMB) have established the standard cosmological model, providing information to understand dark matter and dark energy. In the future, 21cm signals from neutral hydrogen have great potential for cosmological and astrophysical studies. In this talk, I will introduce the scientific goals of the current and future CMB observations and discuss the instrumentation and calibration of two ongoing CMB experiments: the Cosmology Large Angular Scale Surveyor (CLASS) and the Simons Observatory (SO). Then, I will discuss the 21cm signal as a powerful probe to study cosmic reionization and dark ages. I will introduce our novel mapping method and its advantage in recovering the 21cm power spectrum.
Bio: Zhilei Xu (pronunciation link) is interested in answering fundamental questions in physics about dark matter, dark energy, and the early universe by observing primordial radio and microwave signals. He got his Ph.D. from the Johns Hopkins University building the Cosmology Large Angular Scale Surveyor (CLASS) telescopes, to search for signatures of cosmic inflation. His interests in high-resolution CMB sciences then took him to the Simons Observatory (SO) at the University of Pennsylvania building the large aperture telescope receiver (LATR). Always having 21cm cosmology in the back his mind, he then joined the Hydrogen Epoch of Reionization Array (HERA) at MIT to study cosmology with the 21cm emission.