Speaker
Description
There is an observed anisotropy in the arrival direction distribution of cosmic rays in the TeV-PeV regime, with variations on the scale of one part in a thousand. While the origin of this anisotropy is an open question, a possible factor is cosmic-ray interactions with interstellar and heliospheric magnetic fields. These magnetic fields may change over time - for example, due to changes in solar activity throughout its 11-year solar cycle. The cosmic-ray anisotropy can reflect these time-dependent magnetic fields. We first present a novel, model-independent method to detect time variations in the cosmic-ray anisotropy. We then apply this methodology to cosmic-ray data taken by the IceCube Neutrino Observatory from 2011 through 2023, finding time variation in this anisotropy at a significance of greater than 5 sigma (post-trials).