Abstract
In this paper, we show that Bandwidth is hard for the complexity class W[t] for all t∈ N, even for caterpillars with hair length at most three. As intermediate problem, we introduce the Weighted Path Emulation problem: given a vertex-weighted path PN and integer M, decide if there exists a mapping of the vertices of PN to a path PM, such that adjacent vertices are mapped to adjacent or equal vertices, and such that the total weight of the pre-image of a vertex from PM equals an integer c. We show that Weighted Path Emulation, with c as parameter, is hard for W[t] for all t∈ N, and is strongly NP-complete. We also show that Directed Bandwidth is hard for W[t] for all t∈ N, for directed acyclic graphs whose underlying undirected graph is a caterpillar.
Original language | English |
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Title of host publication | Graph-Theoretic Concepts in Computer Science |
Subtitle of host publication | 47th International Workshop, WG 2021, Revised Selected Papers |
Editors | Lukasz Kowalik, Michal Pilipczuk, Pawel Rzazewski |
Publisher | Springer |
Pages | 15-27 |
Number of pages | 13 |
ISBN (Print) | 9783030868376 |
DOIs | |
Publication status | Published - 2021 |
Event | 47th International Workshop on Graph-Theoretic Concepts in Computer Science, WG 2021 - Virtual, Online Duration: 23 Jun 2021 → 25 Jun 2021 |
Publication series
Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
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Volume | 12911 LNCS |
ISSN (Print) | 0302-9743 |
ISSN (Electronic) | 1611-3349 |
Conference
Conference | 47th International Workshop on Graph-Theoretic Concepts in Computer Science, WG 2021 |
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City | Virtual, Online |
Period | 23/06/21 → 25/06/21 |
Bibliographical note
Funding Information:I thank Michael Fellows and Michael Hallett for discussions and earlier joint work on the parameterized complexity of Bandwidth, as reported in [5]. Some techniques in this paper are based upon techniques, underlying the results reported in [5]. I thank Marieke van der Wegen for discussions.
Publisher Copyright:
© 2021, Springer Nature Switzerland AG.
Funding
I thank Michael Fellows and Michael Hallett for discussions and earlier joint work on the parameterized complexity of Bandwidth, as reported in [5]. Some techniques in this paper are based upon techniques, underlying the results reported in [5]. I thank Marieke van der Wegen for discussions.
Keywords
- Bandwidth
- Caterpillars
- Parameterized complexity
- W-hierarchy
- Weighted path emulation