Approximation algorithms for NP-complete problems on planar graphs
Journal of the ACM (JACM)
Efficient approximation schemes for maximization problems on K3,3-free of K5-free graphs
Journal of Algorithms
Node-and edge-deletion NP-complete problems
STOC '78 Proceedings of the tenth annual ACM symposium on Theory of computing
Algorithmic Graph Minor Theory: Decomposition, Approximation, and Coloring
FOCS '05 Proceedings of the 46th Annual IEEE Symposium on Foundations of Computer Science
Subexponential parameterized algorithms on bounded-genus graphs and H-minor-free graphs
Journal of the ACM (JACM)
Dominating Sets in Planar Graphs: Branch-Width and Exponential Speed-Up
SIAM Journal on Computing
Large induced forests in sparse graphs
Journal of Graph Theory
The parameterized complexity of the induced matching problem
Discrete Applied Mathematics
Parameterized complexity of finding regular induced subgraphs
Journal of Discrete Algorithms
Approximation scheme for lowest outdegree orientation and graph density measures
ISAAC'06 Proceedings of the 17th international conference on Algorithms and Computation
Note: Towards optimal kernel for connected vertex cover in planar graphs
Discrete Applied Mathematics
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An induced matching in a graph G=(V,E) is a matching M such that (V,M) is an induced subgraph of G. Clearly, among two vertices with the same neighbourhood (called twins) at most one is matched in any induced matching, and if one of them is matched then there is another matching of the same size that matches the other vertex. Motivated by this, Kanj et al. [10] studied induced matchings in twinless graphs. They showed that any twinless planar graph contains an induced matching of size at least n40 and that there are twinless planar graphs that do not contain an induced matching of size greater than n27+O(1). We improve both these bounds to n28+O(1), which is tight up to an additive constant. This implies that the problem of deciding whether a planar graph has an induced matching of size k has a kernel of size at most 28k. We also show for the first time that this problem is fixed parameter tractable for graphs of bounded arboricity. Kanj et al. also presented an algorithm which decides in O(2^1^5^9^k+n)-time whether an n-vertex planar graph contains an induced matching of size k. Our results improve the time complexity analysis of their algorithm. However, we also show a more efficient O(2^2^5^.^5^k+n)-time algorithm. Its main ingredient is a new, O^*(4^l)-time algorithm for finding a maximum induced matching in a graph of branch width at most l.