Matches in SemOpenAlex for { <https://semopenalex.org/work/W2902679090> ?p ?o ?g. }
Showing items 1 to 76 of
76
with 100 items per page.
- W2902679090 abstract "It has been shown by Bokal et al. that deciding 2-colourability of digraphs is an NP-complete problem. This result was later on extended by Feder et al. to prove that deciding whether a digraph has a circular $p$-colouring is NP-complete for all rational $p>1$. In this paper, we consider the complexity of corresponding decision problems for related notions of fractional colourings for digraphs and graphs, including the star dichromatic number, the fractional dichromatic number and the circular vertex arboricity. We prove the following results: Deciding if the star dichromatic number of a digraph is at most $p$ is NP-complete for every rational $p>1$. Deciding if the fractional dichromatic number of a digraph is at most $p$ is NP-complete for every $p>1, p neq 2$. Deciding if the circular vertex arboricity of a graph is at most $p$ is NP-complete for every rational $p>1$. To show these results, different techniques are required in each case. In order to prove the first result, we relate the star dichromatic number to a new notion of homomorphisms between digraphs, called circular homomorphisms, which might be of independent interest. We provide a classification of the computational complexities of the corresponding homomorphism colouring problems similar to the one derived by Feder et al. for acyclic homomorphisms." @default.
- W2902679090 created "2018-12-11" @default.
- W2902679090 creator A5045347494 @default.
- W2902679090 creator A5048260458 @default.
- W2902679090 creator A5086108469 @default.
- W2902679090 date "2018-12-06" @default.
- W2902679090 modified "2023-09-27" @default.
- W2902679090 title "On the Complexity of Digraph Colourings and Vertex Arboricity." @default.
- W2902679090 cites W1526979981 @default.
- W2902679090 cites W1561272249 @default.
- W2902679090 cites W191023863 @default.
- W2902679090 cites W1965633932 @default.
- W2902679090 cites W2013164124 @default.
- W2902679090 cites W2017363710 @default.
- W2902679090 cites W2020928988 @default.
- W2902679090 cites W2024156610 @default.
- W2902679090 cites W2029126484 @default.
- W2902679090 cites W2130738665 @default.
- W2902679090 cites W2278049421 @default.
- W2902679090 cites W2736950330 @default.
- W2902679090 cites W2962680666 @default.
- W2902679090 cites W2990716873 @default.
- W2902679090 cites W655258421 @default.
- W2902679090 hasPublicationYear "2018" @default.
- W2902679090 type Work @default.
- W2902679090 sameAs 2902679090 @default.
- W2902679090 citedByCount "0" @default.
- W2902679090 crossrefType "posted-content" @default.
- W2902679090 hasAuthorship W2902679090A5045347494 @default.
- W2902679090 hasAuthorship W2902679090A5048260458 @default.
- W2902679090 hasAuthorship W2902679090A5086108469 @default.
- W2902679090 hasConcept C101837359 @default.
- W2902679090 hasConcept C114614502 @default.
- W2902679090 hasConcept C118615104 @default.
- W2902679090 hasConcept C132525143 @default.
- W2902679090 hasConcept C2779145032 @default.
- W2902679090 hasConcept C33923547 @default.
- W2902679090 hasConcept C4042151 @default.
- W2902679090 hasConcept C80899671 @default.
- W2902679090 hasConcept C83204008 @default.
- W2902679090 hasConceptScore W2902679090C101837359 @default.
- W2902679090 hasConceptScore W2902679090C114614502 @default.
- W2902679090 hasConceptScore W2902679090C118615104 @default.
- W2902679090 hasConceptScore W2902679090C132525143 @default.
- W2902679090 hasConceptScore W2902679090C2779145032 @default.
- W2902679090 hasConceptScore W2902679090C33923547 @default.
- W2902679090 hasConceptScore W2902679090C4042151 @default.
- W2902679090 hasConceptScore W2902679090C80899671 @default.
- W2902679090 hasConceptScore W2902679090C83204008 @default.
- W2902679090 hasLocation W29026790901 @default.
- W2902679090 hasOpenAccess W2902679090 @default.
- W2902679090 hasPrimaryLocation W29026790901 @default.
- W2902679090 hasRelatedWork W1485473234 @default.
- W2902679090 hasRelatedWork W1825515612 @default.
- W2902679090 hasRelatedWork W1965721173 @default.
- W2902679090 hasRelatedWork W2014735387 @default.
- W2902679090 hasRelatedWork W2051731147 @default.
- W2902679090 hasRelatedWork W2052776056 @default.
- W2902679090 hasRelatedWork W2052903450 @default.
- W2902679090 hasRelatedWork W2053242449 @default.
- W2902679090 hasRelatedWork W2055646787 @default.
- W2902679090 hasRelatedWork W2061798885 @default.
- W2902679090 hasRelatedWork W2211062586 @default.
- W2902679090 hasRelatedWork W2486271905 @default.
- W2902679090 hasRelatedWork W2555204572 @default.
- W2902679090 hasRelatedWork W2963967898 @default.
- W2902679090 hasRelatedWork W2964328965 @default.
- W2902679090 hasRelatedWork W3001481731 @default.
- W2902679090 hasRelatedWork W3020532734 @default.
- W2902679090 hasRelatedWork W3120604411 @default.
- W2902679090 hasRelatedWork W3163954842 @default.
- W2902679090 hasRelatedWork W3212055365 @default.
- W2902679090 isParatext "false" @default.
- W2902679090 isRetracted "false" @default.
- W2902679090 magId "2902679090" @default.
- W2902679090 workType "article" @default.