On k-visibility graphs
Matthew Babbitt, Jesse Geneson, and Tanya Khovanova
Vol. 19, no. 1, pp. 345-360, 2015. Regular paper.
Abstract We examine several types of visibility graphs in which sightlines can pass through k objects. For k ≥ 1 we bound the maximum thickness of semi-bar k-visibility graphs between ⎡2/3(k + 1) ⎤ and 2k. In addition we show that the maximum number of edges in arc and circle k-visibility graphs on n vertices is at most (k+1)(3nk−2) for n > 4k+4 and (n 2) for n ≤ 4k+4, while the maximum chromatic number is at most 6k+6. In semi-arc k-visibility graphs on n vertices, we show that the maximum number of edges is (n 2) for n ≤ 3k+3 and at most (k+1)(2n−(k+2)/2) for n > 3k+3, while the maximum chromatic number is at most 4k+4.
Submitted: November 2014.
Reviewed: June 2015.
Revised: June 2015.
Accepted: July 2015.
Final: July 2015.
Published: July 2015.
Communicated by Henk Meijer
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