A note on the chromatic number of the square of the Cartesian product of two cyclesShao, Zehui (Avtor) Vesel, Aleksander (Avtor) matematikateorija grafovkromatično številokartezični produktoznačevanje grafovkvadrat grafamathematicsgraph theorychromatic numberCartesian productgraph labelingsquare if a graphThe square ▫$G^2$▫ of a graph ▫$G$▫ is obtained from ▫$G$▫ by adding edges joining all pairs of nodes at distance 2 in ▫$G$▫. In this note we prove that ▫$chi((C_mBox C_n)^2) le 6$ for $m, n ge 40$▫. This confirms Conjecture 19 stated in [É. Sopena, J. Wu, Coloring the square of the Cartesian product of two cycles, Discrete Math. 310 (2010) 2327-2333].20132015-07-10 15:35:28Delo ni kategorizirano52028sl