TY - JOUR

T1 - Subgraphs of graphs on surfaces with high representativity

AU - Kawarabayashi, Ken Ichi

AU - Nakamoto, Atsuhiro

AU - Ota, Katsuhiro

PY - 2003/11

Y1 - 2003/11

N2 - Let G be a 3-connected graph with n vertices on a non-spherical closed surface Fk2 of Euler genus k with sufficiently large representativity. In this paper, we first study a new cutting method which produces a spanning planar subgraph of G with a certain good property. This is used to show that such a graph G has a spanning 4-tree with at most max{2k - 5, 0} vertices of degree 4. Using this result, we prove that for any integer t, if n is sufficiently large, then G has a connected subgraph with t vertices whose degree sum is at most 8t - 1. We also give a nearly sharp bound for the projective plane, torus and Klein bottle. Furthermore, using our cutting method, we prove that a 3-connected graph G on Fk2 with high representativity has a 3-walk in which at most max{2k - 4, 0} vertices are visited three times, and an 8-covering with at most max{4k - 8, 0} vertices of degree 7 or 8. Moreover, a 4-connected G has a 4-covering with at most max[4k - 6, 0} vertices of degree 4.

AB - Let G be a 3-connected graph with n vertices on a non-spherical closed surface Fk2 of Euler genus k with sufficiently large representativity. In this paper, we first study a new cutting method which produces a spanning planar subgraph of G with a certain good property. This is used to show that such a graph G has a spanning 4-tree with at most max{2k - 5, 0} vertices of degree 4. Using this result, we prove that for any integer t, if n is sufficiently large, then G has a connected subgraph with t vertices whose degree sum is at most 8t - 1. We also give a nearly sharp bound for the projective plane, torus and Klein bottle. Furthermore, using our cutting method, we prove that a 3-connected graph G on Fk2 with high representativity has a 3-walk in which at most max{2k - 4, 0} vertices are visited three times, and an 8-covering with at most max{4k - 8, 0} vertices of degree 7 or 8. Moreover, a 4-connected G has a 4-covering with at most max[4k - 6, 0} vertices of degree 4.

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U2 - 10.1016/S0095-8956(03)00072-8

DO - 10.1016/S0095-8956(03)00072-8

M3 - Article

AN - SCOPUS:0344118768

SN - 0095-8956

VL - 89

SP - 207

EP - 229

JO - Journal of Combinatorial Theory. Series B

JF - Journal of Combinatorial Theory. Series B

IS - 2

ER -