Jump To Date
View By Semester
View By Series
Add An Event

Center for Astrophysics Research and Technologies Seminar Series Information


Events Calendar

Cold Dark Matter Caustics

Friday February 18, 2022
3:30 pm

 Presenter:  Pierre Sikivie, Universty of Florida
 Series:  Physics and Astronomy Colloquium
 Abstract:  On a sunny breezy day, sharp lines of light dance on the bottom of a swimming pool. They are due to folds - sometimes called caustics, or catastrophes - in the wavefront of light from the Sun. Caustics also arise naturally in the distribution of dark matter in space. The dark matter density is very large at the location of a caustic.

I'll show that the late infall of cold dark matter onto isolated galaxies, such as our own, produces discrete flows throughout the galactic halo, and associated caustics. One set of caustics are topological spheres surrounding the galaxy. Another set are rings in the galactic plane. Caustic rings are closed tubes whose cross-section is a D_{-4} catastrophe.

I'll argue on theoretical and observational grounds that the caustic ring radii a_n (n=1,2,3..) obey the approximate law: a_n goes like 1/n. There is evidence for these rings in the distribution of bumps in the rotation curves of spiral galaxies, including our own Milky Way. The implications for dark matter searches will be discussed.
 Web Site:    https:/ / youtu.be/ dypKyNPsWpg
 Location:  Via Zoom. Please take the Satisfaction Survey

Disability Notice If you need an auxiliary aid or service to attend any Department of Physics and Astronomy event, please contact the department (phone: 505 277-2616; email: physics@unm.edu) as far in advance as possible to ensure you are accommodated.