title: Neutrinos: the key to ultrahigh energy cosmic rays.
abstract: Observations of ultrahigh energy cosmic rays (UHECR) do not uniquely determine both the injection spectrum and the evolution model for UHECR sources--primarily because interactions during propagation obscure the early Universe from direct observation. Detection of neutrinos produced in those same interactions, coupled with UHECR results, would provide a full description of UHECR source properties.
authors.affiliation: Bartol Research Institute, University of Delaware, Newark, Delaware 19716, USA.
authors.forename: David
authors.initials: D
authors.lastname: Seckel
authors.forename: Todor
authors.initials: T
authors.lastname: Stanev