TY - JOUR ID - Eschouf2015 LB - Eschouf2015 AU - Eschouf, Noureddine Ikhlef AU - Blidia, Mostafa TI - On b-vertex and b-edge critical graphs ST - On b-vertex and b-edge critical graphs JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2015 VL - 35 IS - 2 SP - 171 EP - 180 DO - http://dx.doi.org/10.7494/OpMath.2015.35.2.171 UR - http://dx.doi.org/10.7494/OpMath.2015.35.2.171 AB - A \(b\)-coloring is a coloring of the vertices of a graph such that each color class contains a vertex that has a neighbor in all other color classes, and the \(b\)-chromatic number \(b(G)\) of a graph \(G\) is the largest integer \(k\) such that \(G\) admits a \(b\)-coloring with \(k\) colors. A simple graph \(G\) is called \(b^{+}\)-vertex (edge) critical if the removal of any vertex (edge) of \(G\) increases its \(b\)-chromatic number. In this note, we explain some properties in \(b^{+}\)-vertex (edge) critical graphs, and we conclude with two open problems. KW - \(b\)-coloring KW - \(b\)-chromatic number KW - critical graphs SN - 1232-9274 ER -