Cahit Arf

Cahit Arf was born in 1910 in Selanik(Thessaloniki) which was then a part of the Ottoman Empire. With the outbreak of the Balkan wars in 1912, his family migrated to Istanbul. In 1919 they went to Ankara, came back to Istanbul for a short period and finally settled in Izmir. Professor Arf recollects that his interest in mathematics was aroused during his school years in Izmir. Cahit Arf continued his education in Paris and graduate from Ecole Normale Superieure. Returning to Istanbul, he taught at the Galatasaray Lycee briefly and joined the Mathematics Department of Istanbul University. In 1937 Cahit Arf went to Göttingen for his doctorate which he completed in 1938. His supervisor was H. Hasse.

Cahit Arf returned to Istanbul University where he worked until 1962. During this period he spent one year as a visiting professor at the University of Maryland and was elected a corresponding member of the Mainz Academy. In 1963 he taught at Robert College in Istanbul. Between 1964 and 1966, Professor Arf was at the Institute for Advanced Study in Princeton. After visiting University of California, Berkeley for one year, he returned to Turkey in 1967 and joined the Middle East Technical University in Ankara. In 1980 he retired and lives now in Istanbul.

Professor Arf played a prominent role in establishing the Scientific and Technical Research Council of Turkey and served as its president for many years. From 1985 until 1989 he was the president of the Turkish Mathematical Society. Professor Arf received numerous awards and prizes for his contributions to mathematics and for his most distinguished career, among them the title doctor honoris causa from the Black Sea Technical University, Middle East Technical University and Istanbul Technical University.

Professor Arf has contributed to the education of many of the present day mathematicians in Turkey, not only by his lectures but also through illuminating discussions in conferences and seminars. Those who had the opportunity to come into close contact with Professor Arf, were deeply influenced by his sincere devotion to mathematics and to science in general. Especially for the young mathematicians, he has been a source of sound advice and generous encouragement. For a very brief description of Arf's approach to mathematics let us quote Professor Ikeda.

"To every problem, he has his own idea of approach. The characteristic of his approach is thoroughness; he always seeks invariants, and prefers explicit constructions rather than combination of existing theories. Once he determines his approach, he energetically tackles the problem and never gives up until he achieves his aim. If one studies Cahit Arf's works, which are full of originality and painstaking computations, one will surely wonder where Arf gets his inspirations, and how he gets insight into most complicated computations."

T. Terzioglu

1.C. Arf, Untersuchungen über reinverzweigte Erweiterungen diskret bewerteter perfekter Körper. J. Reine Angew. Math, 181, 1-44 (1939)....................................................................................................	1
2.C. Arf, Untersuchungen über quadratische Formen in Körpern der Charakteristik 2. J.Reine Angew. Math. 183, 148-167 (1941)....................................................................................................................	45
3.C. Arf, Untersuchungen über quadratische Formen in Körper der Charakteristik 2. II. Über aritmetische Aequivalenz quadratischer Formen in Potenzreihenkörpern über einem vollkommenen Körper der Charakteristik 2. Rev. Fac. Sci. Univ. Istanbul (A) 8, 297-327 (1943)...............................................................................................................	65
4.C. Arf, Un théorémé de géométric élémentaire. Rev. Fac. Sci. Univ. Istanbul (A) 12, 153-160 (1947).........................................................................	96
5.C. Arf, Sur les zones de Brillouin. Rev. Fac. Sci. Univ. Istanbul (A) 12, 161-163 (1947)........................................................................	104
6.C. Arf, Sur la détermination des états d'é puilibre d'un millieu élastique plan admettant des frontiéres libres à tensonis constantes. Rev. Fac. Sci. Univ. Istanbul (A) 12, 309-344 (1947).........................................................................	107
7.C. Arf, Sur la définition des déterminants. Université d'Istanbul. Faculté des Sciences. Recueil de mémories commémorant la pose de la premiére pierre des Nouveaux Instituts de la Faculté des Sciences, pp. 9-20, Istanbul 1948...............................................	143
8.C. Arf, Une interprétation algébrique de la suite des ordres de multiplicité d'une branche algébrique. Proc.London Math. soc. (2) 50, 256-287 (1948).....................................................................................	155
9.C. Arf, Sur l'existence de la solution d'un probléme délasticité. Rev. Fac. Sci . Univ. Istanbul (A) 14, 75-85 (1949)............................................................................	187
10.C. Arf, Sur l'identité d'un probléme de frontière libre en élasticité avec un probléme d'é coulement. Bull. Tech. Univ. Istanbul 4 (1951), 1-4 (1952)..................................................................................	198
11.C. Arf, On the methods of Rayleigh-Ritz-Weinstein. Proc. Amer. Math. Soc. 3, 223-232 (1952).......................................................................................	202
12.C. Arf, On the determination of multiply connected domains of an elastic plane body, bounded by free boundaries with constant tangential stresses. Amer. J. Math. 74, 797-820 (1952)....................................................................................................	212
13.C. Arf, Sur un problé me de frontiére libre d'élasticité bidimensionelle, Bull. Tech. Univ. Istanbul 5, (1952), 13-16 (1953)...............................................................................	236
14.C. Arf, Remarques à propos d'un mémoire de K. Erim. Rev. Fac. Sci. Univ. Istanbul (A) 19, 45-54 (1954).............................................................................	240
15.C. Arf, On a generalization of Green?s formula and its application to the Cauchy problem for a hyperbolic equation. Studies in Mathematics and Mechanics presented to Richard von Mises, pp. 69-78. Academic Press Inc., New York, 1954..............................................................................................	250
16.C. Arf, Sur les frontiéres libres à tensions constantes d'un milleu élastique plan en équilibre. Rev. Fac. Sci. Univ. Istanbul Ser. (A) 19, 119-132 (1954)..................................................................	260
17.C. Arf, Sur le théoréme de Reiss. Univ. Roma. Ist. Naz. Alta Mat. e Appl. (5) 14, 181-191 (1954)..................................................................	274
18.C. Arf, Eine explizite Konstruktion der seperablen Hülle eines Potenzreihenkörpes. Abh. Math. Sem. Univ. Hamburg 19, 117-126 (1955).........................................................................	285
19.C. Arf, Über den Satz vor Dubourdieu. Abh. Math. Sem. Univ. Hamburg 20, 112-114 (1955).........................................................................	295
20.C. Arf, Über ein Analogon des Riemann-Rochschen Satzes in Zahlkörpern. Abh. Math. Nat Klasse. Akademie der Wissenschaften und der Literatur in Mainz. No. 9, 293-328 (1957)..................................................................................................................................................	298
21.C. Arf, On the Algebraic Structure of the Cluster Expansion in Statistical Mechanics. (with K. Imre and E. Özizmir) J. Math. Phys. 6, 1179-1188 (1965)...................................................................................................	334
22.C. Arf, Due dimostrazioni elementari del teorema di Cartan e Dieudonné (with G. Saban) Rivista Math. Univ. Parma 6, 169-223 (1965).....................................................................................	344
23.C. Arf, Sur la structure du groupe de Galois de la fermeture algébrique d'un corps de séries de puissances sur un corps fini et les conducteurs d'Artin. Les Tendance Géom. en Algébre et Théories des Nombres, pp. 27-35. Editions du CNRS, Paris, (1966).............................................................................	399

1. Topics in Algebraic Number Theory. Masatoshi G. Ikeda..........................................................................................................................	410
2. Arf invariant and its applicstions in topology Turgut Onder .......................................................................................	413
3. On Arf rings Sinan Sertoz....................................................................................................................................	416
4. Arf's work in Applied Mathematics Cem Tezer...................................................................................................	420