We have decided to discontinue the publication of preprints on our preprint server end of 2024. The publication culture within mathematics has changed so much due to the rise of repositories such as ArXiV (www.arxiv.org) that we are encouraging all institute members to make their preprints available there. An institute's repository in its previous form is, therefore, unnecessary. The preprints published to date will remain available here, but we will not add any new preprints here.
The aim of this paper is to explain phenomena in the reversal of the magnetization in nanowires. In numerical simulations two different reversal modes have been found, one occurring for very thin, the other for thicker wires. We study the two modes analytically and investigate the reasons why they occur.