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Upper signed domination number
Let G = ( V , E ) be a graph. A signed dominating function on G is a function f : V → { - 1 , 1 } such that ∑ u ∈ N [ v ] f ( u ) ⩾ 1 for each v ∈ V , where N [ v ] is the closed neighborhood of v . The weight of a signed dominating function f is ∑ v ∈ V f ( v ) . A signed dominating function f is m...
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Published in: | Discrete mathematics 2008-08, Vol.308 (15), p.3416-3419 |
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Main Authors: | , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Let
G
=
(
V
,
E
)
be a graph. A signed dominating function on
G is a function
f
:
V
→
{
-
1
,
1
}
such that
∑
u
∈
N
[
v
]
f
(
u
)
⩾
1
for each
v
∈
V
, where
N
[
v
]
is the closed neighborhood of
v
. The weight of a signed dominating function
f is
∑
v
∈
V
f
(
v
)
. A signed dominating function
f is minimal if there exists no signed dominating function
g such that
g
≠
f
and
g
(
v
)
⩽
f
(
v
)
for each
v
∈
V
. The upper signed domination number of a graph
G, denoted by
Γ
s
(
G
)
, equals the maximum weight of a minimal signed dominating function of
G. In this paper, we establish an tight upper bound for
Γ
s
(
G
)
in terms of minimum degree and maximum degree. Our result is a generalization of those for regular graphs and nearly regular graphs obtained in [O. Favaron, Signed domination in regular graphs, Discrete Math. 158 (1996) 287–293] and [C.X. Wang, J.Z. Mao, Some more remarks on domination in cubic graphs, Discrete Math. 237 (2001) 193–197], respectively. |
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ISSN: | 0012-365X 1872-681X |
DOI: | 10.1016/j.disc.2007.06.031 |