On minimal triangle-free graphs with prescribed k-defective chromatic number

A graph G is (m, k)-colourable if its vertices can be coloured with m colours such that the maximum degree of any subgraph induced on vertices receiving the same colour is at most k. The k-defective chromatic number χk(G) is the least positive integer m for which G is (m, k)-colourable. Let f(m, k)...

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Main Authors: Achuthan, Nirmala, Achuthan, Narasimaha, Simanihuruk, M.
Format: Journal Article
Published: Elsevier Science BV 2011
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/24432
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author Achuthan, Nirmala
Achuthan, Narasimaha
Simanihuruk, M.
author_facet Achuthan, Nirmala
Achuthan, Narasimaha
Simanihuruk, M.
author_sort Achuthan, Nirmala
building Curtin Institutional Repository
collection Online Access
description A graph G is (m, k)-colourable if its vertices can be coloured with m colours such that the maximum degree of any subgraph induced on vertices receiving the same colour is at most k. The k-defective chromatic number χk(G) is the least positive integer m for which G is (m, k)-colourable. Let f(m, k) be the smallest order of a triangle-free graph such that χk(G)=m. In this paper we study the problem of determining f(m, k). We show that f(3, 2)=13 and characterize the corresponding minimal graphs. We present a lower bound for f(m, k) for all m≥3 and also an upper bound for f(3, k).
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institution Curtin University Malaysia
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publishDate 2011
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spelling curtin-20.500.11937-244322017-09-13T15:52:51Z On minimal triangle-free graphs with prescribed k-defective chromatic number Achuthan, Nirmala Achuthan, Narasimaha Simanihuruk, M. k-defective chromatic number Triangle-free graphs k-independence A graph G is (m, k)-colourable if its vertices can be coloured with m colours such that the maximum degree of any subgraph induced on vertices receiving the same colour is at most k. The k-defective chromatic number χk(G) is the least positive integer m for which G is (m, k)-colourable. Let f(m, k) be the smallest order of a triangle-free graph such that χk(G)=m. In this paper we study the problem of determining f(m, k). We show that f(3, 2)=13 and characterize the corresponding minimal graphs. We present a lower bound for f(m, k) for all m≥3 and also an upper bound for f(3, k). 2011 Journal Article http://hdl.handle.net/20.500.11937/24432 10.1016/j.disc.2010.08.013 Elsevier Science BV unknown
spellingShingle k-defective chromatic number
Triangle-free graphs
k-independence
Achuthan, Nirmala
Achuthan, Narasimaha
Simanihuruk, M.
On minimal triangle-free graphs with prescribed k-defective chromatic number
title On minimal triangle-free graphs with prescribed k-defective chromatic number
title_full On minimal triangle-free graphs with prescribed k-defective chromatic number
title_fullStr On minimal triangle-free graphs with prescribed k-defective chromatic number
title_full_unstemmed On minimal triangle-free graphs with prescribed k-defective chromatic number
title_short On minimal triangle-free graphs with prescribed k-defective chromatic number
title_sort on minimal triangle-free graphs with prescribed k-defective chromatic number
topic k-defective chromatic number
Triangle-free graphs
k-independence
url http://hdl.handle.net/20.500.11937/24432