Publications by authors named "T Gregoire"

The origin of high-energy cosmic rays, atomic nuclei that continuously impact Earth's atmosphere, is unknown. Because of deflection by interstellar magnetic fields, cosmic rays produced within the Milky Way arrive at Earth from random directions. However, cosmic rays interact with matter near their sources and during propagation, which produces high-energy neutrinos.

View Article and Find Full Text PDF

Though substantial research has been conducted on possible historical, physiological, and symbiotic mechanisms that permit monodominance to occur within tropical lowland rainforests, less is known about the successional rates at which monodominance exerts itself on surrounding forest structures. Here we extend efforts to evaluate the longitudinal dynamics of Gilbertiodendron dewevrei-dominated forest in Central Africa by considering this species' spatial dynamics. Using three 10-ha censused field plots measured across three time periods, we present the first quantitative estimates of the spatial propagation of Gilbertiodendron into adjacent mixed species forest.

View Article and Find Full Text PDF
Article Synopsis
  • A supermassive black hole in the galaxy NGC 1068, hidden by cosmic dust, is believed to power its active core, and neutrinos might help us understand this.
  • Researchers analyzed data from the IceCube neutrino detector from 2011 to 2020 to detect neutrinos from various gamma-ray sources, including NGC 1068.
  • They discovered an excess of high-energy neutrinos from NGC 1068, indicating a significant connection to the galaxy's activity, and these neutrinos were found to be much more abundant than previously measured gamma rays from the same source.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates the presence of an unstable sterile neutrino using eight years of atmospheric muon neutrino data collected at the IceCube Neutrino Observatory.
  • Results indicate that both traditional three-neutrino models and 3+1 sterile neutrino models are less favored compared to the unstable sterile neutrino model, but no significant evidence for 3+1 neutrinos with decay was found.
  • The research provides specific parameters for the unstable sterile neutrino model, while also excluding favored regions of the 3+1 model from prior short-baseline oscillation studies.
View Article and Find Full Text PDF

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{μτ}. The best-fit value is consistent with no NSI at a p value of 25.

View Article and Find Full Text PDF