Effective Coloration
Bean, Dwight R.
J. Symbolic Logic, Tome 41 (1976) no. 1, p. 469-480 / Harvested from Project Euclid
We are concerned here with recursive function theory analogs of certain problems in chromatic graph theory. The motivating question for our work is: Does there exist a recursive (countably infinite) planar graph with no recursive 4-coloring? We obtain the following results: There is a 3-colorable, recursive planar graph which, for all $k$, has no recursive $k$-coloring; every decidable graph of genus $p \geq 0$ has a recursive $2(\chi(p) - 1)$-coloring, where $\chi(p)$ is the least number of colors which will suffice to color any graph of genus $p$; for every $k \geq 3$ there is a $k$-colorable, decidable graph with no recursive $k$-coloring, and if $k = 3$ or if $k = 4$ and the 4-color conjecture fails the graph is planar; there are degree preserving correspondences between $k$-colorings of graphs and paths through special types of trees which yield information about the degrees of unsolvability of $k$-colorings of graphs.
Publié le : 1976-06-14
Classification: 
@article{1183739789,
     author = {Bean, Dwight R.},
     title = {Effective Coloration},
     journal = {J. Symbolic Logic},
     volume = {41},
     number = {1},
     year = {1976},
     pages = { 469-480},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1183739789}
}
Bean, Dwight R. Effective Coloration. J. Symbolic Logic, Tome 41 (1976) no. 1, pp.  469-480. http://gdmltest.u-ga.fr/item/1183739789/