On Longest Cycles in Essentially 4-Connected Planar Graphs
A planar 3-connected graph G is essentially 4-connected if, for any 3-separator S of G, one component of the graph obtained from G by removing S is a single vertex. Jackson and Wormald proved that an essentially 4-connected planar graph on n vertices contains a cycle C such that . For a cubic essent...
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Format: | Article |
Language: | English |
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University of Zielona Góra
2016-08-01
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Series: | Discussiones Mathematicae Graph Theory |
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Online Access: | https://doi.org/10.7151/dmgt.1875 |
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author | Fabrici Igor Harant Jochen Jendroľ Stanislav |
author_facet | Fabrici Igor Harant Jochen Jendroľ Stanislav |
author_sort | Fabrici Igor |
collection | DOAJ |
description | A planar 3-connected graph G is essentially 4-connected if, for any 3-separator S of G, one component of the graph obtained from G by removing S is a single vertex. Jackson and Wormald proved that an essentially 4-connected planar graph on n vertices contains a cycle C such that . For a cubic essentially 4-connected planar graph G, Grünbaum with Malkevitch, and Zhang showed that G has a cycle on at least ¾ n vertices. In the present paper the result of Jackson and Wormald is improved. Moreover, new lower bounds on the length of a longest cycle of G are presented if G is an essentially 4-connected planar graph of maximum degree 4 or G is an essentially 4-connected maximal planar graph. |
first_indexed | 2024-03-12T08:44:28Z |
format | Article |
id | doaj.art-00c53a1b75f6495ca1f93b22bcedef76 |
institution | Directory Open Access Journal |
issn | 2083-5892 |
language | English |
last_indexed | 2024-03-12T08:44:28Z |
publishDate | 2016-08-01 |
publisher | University of Zielona Góra |
record_format | Article |
series | Discussiones Mathematicae Graph Theory |
spelling | doaj.art-00c53a1b75f6495ca1f93b22bcedef762023-09-02T16:29:58ZengUniversity of Zielona GóraDiscussiones Mathematicae Graph Theory2083-58922016-08-0136356557510.7151/dmgt.1875dmgt.1875On Longest Cycles in Essentially 4-Connected Planar GraphsFabrici Igor0Harant Jochen1Jendroľ Stanislav2Institute of Mathematics P.J. Šafárik University in Košice, SlovakiaInstitute of Mathematics Ilmenau University of Technology, GermanyInstitute of Mathematics P.J. Šafárik University in Košice, SlovakiaA planar 3-connected graph G is essentially 4-connected if, for any 3-separator S of G, one component of the graph obtained from G by removing S is a single vertex. Jackson and Wormald proved that an essentially 4-connected planar graph on n vertices contains a cycle C such that . For a cubic essentially 4-connected planar graph G, Grünbaum with Malkevitch, and Zhang showed that G has a cycle on at least ¾ n vertices. In the present paper the result of Jackson and Wormald is improved. Moreover, new lower bounds on the length of a longest cycle of G are presented if G is an essentially 4-connected planar graph of maximum degree 4 or G is an essentially 4-connected maximal planar graph.https://doi.org/10.7151/dmgt.1875planar graphlongest cycle |
spellingShingle | Fabrici Igor Harant Jochen Jendroľ Stanislav On Longest Cycles in Essentially 4-Connected Planar Graphs Discussiones Mathematicae Graph Theory planar graph longest cycle |
title | On Longest Cycles in Essentially 4-Connected Planar Graphs |
title_full | On Longest Cycles in Essentially 4-Connected Planar Graphs |
title_fullStr | On Longest Cycles in Essentially 4-Connected Planar Graphs |
title_full_unstemmed | On Longest Cycles in Essentially 4-Connected Planar Graphs |
title_short | On Longest Cycles in Essentially 4-Connected Planar Graphs |
title_sort | on longest cycles in essentially 4 connected planar graphs |
topic | planar graph longest cycle |
url | https://doi.org/10.7151/dmgt.1875 |
work_keys_str_mv | AT fabriciigor onlongestcyclesinessentially4connectedplanargraphs AT harantjochen onlongestcyclesinessentially4connectedplanargraphs AT jendrolstanislav onlongestcyclesinessentially4connectedplanargraphs |