144 research outputs found
Degree Sequence Index Strategy
We introduce a procedure, called the Degree Sequence Index Strategy (DSI), by
which to bound graph invariants by certain indices in the ordered degree
sequence. As an illustration of the DSI strategy, we show how it can be used to
give new upper and lower bounds on the -independence and the -domination
numbers. These include, among other things, a double generalization of the
annihilation number, a recently introduced upper bound on the independence
number. Next, we use the DSI strategy in conjunction with planarity, to
generalize some results of Caro and Roddity about independence number in planar
graphs. Lastly, for claw-free and -free graphs, we use DSI to
generalize some results of Faudree, Gould, Jacobson, Lesniak and Lindquester
Dynamic approach to k-forcing
The k-forcing number of a graph is a generalization of the zero forcing
number. In this note, we give a greedy algorithm to approximate the k-forcing
number of a graph. Using this dynamic approach, we give corollaries which
improve upon two theorems from a recent paper of Amos, Caro, Davila and Pepper
[2], while also answering an open problem posed by Meyer [9]
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