3,264 research outputs found
Brownian Manifolds, Negative Type and Geo-temporal Covariances
We survey Brownian manifolds -- manifolds that can parametrise Brownian
motion -- and those that cannot. We consider covariances of space-time
processes, particularly those when space is the sphere -- geo-temporal
processes. There are connections with functions of negative type.Comment: 12 pages; corrected typos and acknowledgemen
Implications of new measurements of O-16 + p + C-12,13, N-14,15 for the abundances of C, N isotopes at the cosmic ray source
The fragmentation of a 225 MeV/n O-16 beam was investigated at the Bevalac. Preliminary cross sections for mass = 13, 14, 15 fragments are used to constrain the nuclear excitation functions employed in galactic propagation calculations. Comparison to cosmic ray isotonic data at low energies shows that in the cosmic ray source C-13/C approximately 2% and N-14/0=3-6%. No source abundance of N-15 is required with the current experimental results
- …