| A review of the current state of ultra-high energy (UHE) cosmic ray physics is followed by a presentation of some recent work in this field. A method of using Fourier analysis to obtain limits on the rest masses of cosmic ray particles from point sources is presented, along with a specific example using data from Hercules X-1. An upper limit of approximately 33 MeV is obtained from this data. Following is an analysis of the effects of microwave absorption on the flux of cosmic ray photons. Data from Cygnus X-3 is analyzed to determine the level of agreement with current assumptions about the source and composition of the flux. It is found to be statistically likely that the flux contains a component which is not absorbed by the background microwave radiation. A toy model for the development of atmospheric showers is presented next and applied to the case of "anomalous" showers which are hypothesized to be initiated by non-standard particle interactions. It is found that primary interactions with cross sections smaller than the average standard hadronic interactions, and which initiate showers lower in the atmosphere, leave telltale signs in the lateral distribution of muons. The suggestion that neutrinos exhibiting new particle interactions might be responsible for the observation of "anomalous" showers leads to an investigation of the galactic neutrino background. The background flux of cosmic neutrinos is estimated, considering first the known matter density in the galaxy, and then the halo of baryonic dark matter which is believed to exist in and around the galaxy. |
