{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T14:42:02Z","timestamp":1787323322508,"version":"build-2736575974"},"reference-count":4,"publisher":"Society for Industrial & Applied Mathematics (SIAM)","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["SIAM J. Discrete Math."],"published-print":{"date-parts":[[2007,1]]},"abstract":"<jats:p>The unit distance graph $\\mathcal{R}$ is the graph with vertex set $\\mathbb{R}^2$ in which two vertices (points in the plane) are adjacent if and only if they are at Euclidean distance 1. We prove that the circular chromatic number of $\\mathcal{R}$ is at least 4, thus improving the known lower bound of $32\/9$ obtained from the fractional chromatic number of $\\mathcal{R}$.<\/jats:p>","DOI":"10.1137\/060664276","type":"journal-article","created":{"date-parts":[[2007,5,25]],"date-time":"2007-05-25T13:18:27Z","timestamp":1180099107000},"page":"461-465","source":"Crossref","is-referenced-by-count":2,"title":["Circular Coloring the Plane"],"prefix":"10.1137","volume":"21","author":[{"given":"Matt","family":"DeVos","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Javad","family":"Ebrahimi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohammad","family":"Ghebleh","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luis","family":"Goddyn","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bojan","family":"Mohar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Reza","family":"Naserasr","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"351","published-online":{"date-parts":[[2007,5,22]]},"reference":[{"key":"R1","unstructured":"H. Hadwiger and H. Debrunner,\n                      Combinatorial Geometry in the Plane\n                      , Holt, Rinehart and Winston, New York, 1964."},{"key":"R2","doi-asserted-by":"crossref","unstructured":"L. Moser and W. Moser,\n                      Solution to problem\n                      10, Canad. Math. Bull., 4 (1961), pp. 187\u2013189.","DOI":"10.1017\/S0008439500025753"},{"key":"R3","unstructured":"E. R. Scheinerman and D. H. Ullman,\n                      Fractional Graph Theory\n                      , John Wiley & Sons, New York, 1997."},{"key":"R4","doi-asserted-by":"publisher","DOI":"10.1016\/S0012-365X(00)00217-X"}],"container-title":["SIAM Journal on Discrete Mathematics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/epubs.siam.org\/doi\/pdf\/10.1137\/060664276","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T13:55:26Z","timestamp":1787320526000},"score":1,"resource":{"primary":{"URL":"https:\/\/epubs.siam.org\/doi\/10.1137\/060664276"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2007,1]]},"references-count":4,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2007,1]]}},"alternative-id":["10.1137\/060664276"],"URL":"https:\/\/doi.org\/10.1137\/060664276","relation":{},"ISSN":["0895-4801","1095-7146"],"issn-type":[{"value":"0895-4801","type":"print"},{"value":"1095-7146","type":"electronic"}],"subject":[],"published":{"date-parts":[[2007,1]]}}}