@article{900cc1c273094900afd6d697c881539e,
title = "Induced subgraphs of graphs with large chromatic number. XI. Orientations",
abstract = "Fix an oriented graph H, and let G be a graph with bounded clique number and very large chromatic number. If we somehow orient its edges, must there be an induced subdigraph isomorphic to H? Kierstead and R{\"o}dl (1996) raised this question for two specific kinds of digraph H: the three-edge path, with the first and last edges both directed towards the interior; and stars (with many edges directed out and many directed in). Aboulker et al. (2018) subsequently conjectured that the answer is affirmative in both cases. We give affirmative answers to both questions.",
author = "Maria Chudnovsky and Alex Scott and Paul Seymour",
note = "Funding Information: The first author was supported by NSF , United States grant DMS-1550991 and US Army Research Office Grant W911NF-16-1-0404 . The second author was supported by a Leverhulme Trust Research Fellowship , United Kingdom. The third author was supported by ONR , United States grant N00014-14-1-0084 and NSF , United States grant DMS-1265563 . Funding Information: The first author was supported by NSF, United States grant DMS-1550991 and US Army Research Office Grant W911NF-16-1-0404. The second author was supported by a Leverhulme Trust Research Fellowship, United Kingdom. The third author was supported by ONR, United States grant N00014-14-1-0084 and NSF, United States grant DMS-1265563. Publisher Copyright: {\textcopyright} 2018 Elsevier Ltd",
year = "2019",
month = feb,
doi = "10.1016/j.ejc.2018.09.003",
language = "English (US)",
volume = "76",
pages = "53--61",
journal = "European Journal of Combinatorics",
issn = "0195-6698",
publisher = "Academic Press Inc.",
}