Rudolf Halin
Rudolf Halin (February 3, 1934 – November 14, 2014) was a German graph theorist, known for defining the ends of infinite graphs,[1] for Halin's grid theorem,[2][3] for extending Menger's theorem to infinite graphs,[4] and for his early research on treewidth and tree decomposition.[5] He is also the namesake of Halin graphs, a class of planar graphs constructed from trees by adding a cycle through the leaves of the given tree; earlier researchers had studied the subclass of cubic Halin graphs but Halin was the first to study this class of graphs in full generality.[6]
Life
Halin was born on February 3, 1934, in Uerdingen.[7] He earned his doctorate from the University of Cologne in 1962, under the supervision of Klaus Wagner and Karl Dörge, after which he joined the faculty of the University of Hamburg.[8] He died on November 14, 2014, in Mölln, Schleswig-Holstein.[7]
Recognition
In February 1994, a colloquium was held at the University of Hamburg in honor of Halin's 60th birthday.[9] In 2017, a special issue of the journal Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg was published in his memory.[10]
Selected publications
Research papers
- Halin, R. (1964), "Über unendliche Wege in Graphen", S2CID 122125458.
- Halin, R. (1965), "Über die Maximalzahl fremder unendlicher Wege in Graphen", MR 0190031.
- Halin, R. (1971), "Studies on minimally n-connected graphs", Combinatorial Mathematics and its Applications (Proc. Conf., Oxford, 1969), London: Academic Press, pp. 129–136, MR 0278980.
- Halin, R. (1974), "A note on Menger's theorem for infinite locally finite graphs", Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg, 40: 111–114, S2CID 120915644.
- Halin, R. (1976), "S-functions for graphs", Journal of Geometry, 8 (1–2): 171–186, S2CID 120256194.
Textbooks
- Halin, R., Graphentheorie. Vols. I and II published in 1980 and 1981 respectively by Wissenschaftliche Buchgesellschaft.[11] Combined 2nd ed. published in 1989 by Wissenschaftliche Buchgesellschaft.[12]
References
- ^ Halin (1964).
- ^ Halin (1965).
- S2CID 124603912.
- ^ Halin (1974).
- ^ Halin (1976).
- ^ Halin (1971).
- ^ a b Diestel, Reinhard (December 7, 2014), Rudolf Halin 1934–2014, DMANET mailing list. Date corrected in a follow-up email from Diestel. Birthplace from his books Graphentheorie I, II.
- ^ Rudolf Halin at the Mathematics Genealogy Project
- ^ Mathematisches Seminar, Univ. of Hamburg, retrieved 2013-02-19.
- MR 3696145
- MR0668698.
- MR1068314.