http://openproblemgarden.org/op/high_girth_low_degree_4_chromatic_graphs Comments for "4-regular 4-chromatic graphs of high girth" en http://openproblemgarden.org/op/high_girth_low_degree_4_chromatic_graphs#comment-7134 <p>Your list of 4 regular 4 chromatic graphs with girth >= 4 is not complete. Check "A note on 4-regular 4 chromatic graphs with girth 4" http://math.nju.edu.cn/~zkmfl/kmzhang/41-60/Zhang44.pdf. Girth 5 is known too.</p> Sun, 29 Jan 2012 15:14:35 +0100 Anonymous comment 7134 at http://openproblemgarden.org http://openproblemgarden.org/op/high_girth_low_degree_4_chromatic_graphs#comment-3265 <p>What maximum degree is needed in a triangle-free graph (or higher girth) with chromatic number 5? What about chromatic number 6 and 7? Are good bounds known on these maximum degrees?</p> Thu, 13 Nov 2008 13:27:03 +0100 Anonymous comment 3265 at http://openproblemgarden.org http://openproblemgarden.org/op/high_girth_low_degree_4_chromatic_graphs <table cellspacing="10"> <tr> <td> Author(s): <a href="/category/grunbaum">Grunbaum</a>&nbsp;&nbsp; </td> <td align=right> Subject: <a href="/category/graph_theory">Graph Theory</a> » <a href="/category/coloring">Coloring</a>&nbsp;&nbsp; </td> </tr> <tr> <td colspan=2> <table border=1 cellspacing="5"> <tr><td> <div class="envtheorem"><b>Problem</b>&nbsp;&nbsp; Do there exist 4-regular 4-chromatic graphs of arbitrarily high girth? </div> </tr></td> </table> </td> </tr> </table> Grunbaum, Branko coloring girth Graph Theory Coloring http://openproblemgarden.org/op/high_girth_low_degree_4_chromatic_graphs#comment Wed, 18 Jun 2008 08:43:59 +0200 mdevos 830 at http://openproblemgarden.org