Events on Wednesday, January 29th, 2020
- Department Meeting
- Time: 12:15 pm - 1:15 pm
- Place: B343 Sterling Hall
- Speaker: Sridhara Dasu, Department Chair
- Host: Sridhara Dasu
- Atomic Physics Seminar
- Results and challenges from a Helium-Neon comagnetometer with SERF readout
- Time: 1:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: William Terrano, Princeton
- Abstract: We have built a comagnetometer that compares Helium-3 and Neon-21 precession frequencies using a SERF magnetometer. Spin-exchange interactions are suppressed with a sequence of RF pulses. I will discuss the operation of the system, and our current sensitivity, which has reached 7 nHz in 2000 seconds and below 1 nHz in a day. I will discuss several important experimental techniques that allowed us to reach that level, as well as some outstanding challenges and unexplained phenomena.
- Host: Thrasher
- Theory Seminar (High Energy/Cosmology)
- Fundamental physics with CMB and galaxy surveys
- Time: 4:00 pm
- Place: 5280 Chamberlin
- Speaker: Moritz Münchmeyer, Perimeter
- Abstract: Upcoming experiments such as the Simons Observatory, DESI and LSST probe the universe with extremely high resolution. This upcoming data provides us with great opportunities for fundamental physics, such as probing the initial conditions of the universe. However, the vastness and extreme complexity of this interrelated data requires new methods to make sense of it. I will describe two ways forward, one based on theoretical understanding and one based on computation. In the former, I show how CMB and galaxy data can be combined in a new way to give unprecedentedly tight constraints on aspects of primordial physics. In the latter, I describe a step towards performing precision cosmology with machine learning, in a way that builds on the powerful physical and statistical methodology that has led to the success of observational cosmology.
- Host: Dan Chung