Cycles in weighted graphs and related topics

This thesis contains results on paths andcycles in graphs andon a more or less relatedtopic, the vulnerability of graphs. In the first part of the thesis, Chapters 2 through 5, we concentrate on paths andcycles in weightedgraphs. A number of sufficient conditions are presentedfor graphs to contain paths andcycles with certain properties, in particular heavy (or long) paths andcycles. The secondpart of the thesis, Chapters 6 and7, contains some basic results on paths andcycles in (edge-) colored graphs. In the thirdpart of the thesis, Chapters 8 and9, we focus on a graph parameter which can be usedto analyze the vulnerability of graphs, i.e., the scattering number of graphs.