IAS High Energy Theory Seminar
The Cosmic Neutrino Background (CνB): Its Distribution on the Surface of the Earth and its Manipulation by Laboratory-Scale Diffraction Gratings
This seminar will be presented in-person and on Zoom.
https://theias.zoom.us/j/84116605050?pwd=VHV6VkRUM3hkM2dFSlo2QWJiUWtPdz09
Abstract: The CνB is a cosmological relic analogous to the CMB, and contains information about the universe before it was one-second-old. Reflection of relic neutrinos from the surface of the Earth creates a significant local neutrino-antineutrino asymmetry in a shell seven meters thick around the Earth's surface. This asymmetry far exceeds the expected primordial lepton asymmetry. The resulting gradient of the net neutrino density evades the forty-year-old “no-go” theorem on the vanishing of O(G_Fermi) neutrino forces on matter.
These forces can be further enhanced by using 1-100 meter structures with shape reminiscent of a sea-urchin: they consist of rods of width w and length L>>w periodically arranged on the surface of the sphere of radius R~L. Such a structure functions as a diffraction grating for relic neutrinos and the induced neutrino-antineutrino asymmetry at its center may point to a new class of experiments to detect the CνB in a laboratory setting. At the same time, such structures can be used to similarly manipulate dark matter.