482 research outputs found
Coloring Graphs Drawn with Crossings
This dissertation will examine various results for graph colorings. It begins by introducing some basic graph theory concepts, focusing on those ideas relevant to graph embeddings, and by introducing terminology to allow a formal discussion of drawings of graphs. Chapter 2 focuses on results for proper colorings of graphs with good drawings, using a previous result from Král and Stacho as inspiration. Chapter 3 expands on the ideas of Chapter 2 and focuses on cyclic colorings of embedded graphs. Chapters 5 and 6 examine results for total and list colorings, respectively, of drawings of graphs. Finally, Chapter 6 introduces generalized pseudosurfaces and examines results for proper and cyclic colorings of graphs embedded in generalized pseudosurfaces
Fine structure of 4-critical triangle-free graphs III. General surfaces
Dvo\v{r}\'ak, Kr\'al' and Thomas gave a description of the structure of
triangle-free graphs on surfaces with respect to 3-coloring. Their description
however contains two substructures (both related to graphs embedded in plane
with two precolored cycles) whose coloring properties are not entirely
determined. In this paper, we fill these gaps.Comment: 15 pages, 1 figure; corrections from the review process. arXiv admin
note: text overlap with arXiv:1509.0101
- …