TY - JOUR
AU - Miklós Ujvári
PY - 2012/01/01
Y2 - 2023/11/30
TI - New descriptions of the Lovász number, and the weak sandwich theorem
JF - Acta Cybernetica
JA - Acta Cybern
VL - 20
IS - 4
SE - Regular articles
DO - 10.14232/actacyb.20.4.2012.3
UR - https://cyber.bibl.u-szeged.hu/index.php/actcybern/article/view/3824
AB - In 1979, L. Lovász introduced the concept of an orthonormal representation of a graph, and also a related value, now popularly known as the Lovász number of the graph. One of the remarkable properties of the Lovász number is that it lies sandwiched between the stability number of the graph and the chromatic number of the complementary graph. This fact is called the sandwich theorem. In this paper, using new descriptions of the Lovász number and linear algebraic lemmas we give three proofs for a weaker version of the sandwich theorem.
ER -