Record number :

1526720

Title of article :

Vertex Set Partitions Preserving Conservativeness

Author/Authors :

Ageev، نويسنده , , A.A. and Kostochka، نويسنده , , A.V.، نويسنده ,

Issue Information :

روزنامه با شماره پیاپی سال 2000

Pages :

16

From page :

202

To page :

217

Abstract :

Let G be an undirected graph and P={X1, …, Xn} be a partition of V(G). Denote by G/P the graph which has vertex set {X1, …, Xn}, edge set E, and is obtained from G by identifying vertices in each class Xi of the partition P. Given a conservative graph (G, w), we study vertex set partitions preserving conservativeness, i.e., those for which (G/P, w) is also a conservative graph. We characterize the conservative graphs (G/P, w), where P is a terminal partition of V(G) (a partition preserving conservativeness which is not a refinement of any other partition of this kind). We prove that many conservative graphs admit terminal partitions with some additional properties. The results obtained are then used in new unified short proofs for a co-NP characterization of Seymour graphs by A. A. Ageev, A. V. Kostochka, and Z. Szigeti (1997, J. Graph Theory34, 357–364), a theorem of E. Korach and M. Penn (1992, Math. Programming55, 183–191), a theorem of E. Korach (1994, J. Combin. Theory Ser. B62, 1–10), and a theorem of A. V. Kostochka (1994, in “Discrete Analysis and Operations Research. Mathematics and its Applications (A. D. Korshunov, Ed.), Vol. 355, pp. 109–123, Kluwer Academic, Dordrecht).

Keywords :

Undirected graph , T-join , T-cut , conservative weighting

Journal title :

Journal of Combinatorial Theory Series B

Serial Year :

2000

Link To Document :