The circular chromatic number of distance graphs with

Download PDF
1 downloads 0 Views 223KB Size Report
Comment
coloured with distinct colours. This problem is equivalent to determining the chromatic number of the distance graph G(R2, {1}) on the plane R2 with distance set ...
     

                        

                     !"#$#        

                

               

                                   ! " #   $ %                  

            & % &    ' % (      % ) * % +,,-.   / (       % # &  % +,,,.   Æ      

     



      !    !     "

! #     ! $   %! "  

                

 

  &      '    # !       (  )      *%       *       #      +        $        !      ,! ,  . / 0!  *        1        #         #       *  #               +    2 *        #       (   )           3   4  .  5  ((   ))  6!   %  *  # ((   ))  . '     

   !      # (  )      #   7 /7! 80 4#  3      #       (( )) 3 79 #        *   (( )) 3 : 4#    "    !    

2 *             (#         )!  ((  )) 3 7 (#     

   ) 4#           !      # (  )    /70 +             + 

*   /7! ! ! 8! 0 

   !       *   '   !        

 *  / 0!      3      ; 3  *  /70!      3       7  *  /7! ! 80!      3      7   *  / 0!      3        *  / 0 +  

    !      **     # !    *  /7! ! 80