title: Walter Borho
text: # Walter Borho
  
  Walter Borho (born 17 December 1945, in Hamburg) is a German mathematician, who works on algebra and number theory.
  
  Borho received his PhD in 1973 from the University of Hamburg under the direction of Ernst Witt with thesis Wesentliche ganze Erweiterungen kommutativer Ringe. He is a professor at the University of Wuppertal.
  
  Borho does research on representation theory, Lie algebras, ring theory and also on number theory (amicable numbers) and tilings.
  
  In 1986 he was an invited speaker at the International Congress of Mathematicians in Berkeley (Nilpotent orbits, primitive ideals and characteristic classes – a survey).
  
  ## Publications
  
  * Borho, Walter (1972). "On Thabit ibn Kurrah's formula for amicable numbers". Math. Comp. 26 (118): 571–578. doi:10.2307/2005185. JSTOR 2005185. MR 0313177.
  * Borho, Don Zagier et al.: Lebendige Zahlen, Birkhäuser 1981 (containing Borho's Befreundete Zahlen [Amicable Numbers])
  * with Peter Gabriel, Rudolf Rentschler: Primideale in Einhüllenden auflösbarer Lie-Algebren, Springer Verlag, Lecture Notes in Mathematics, vol. 357, 1973
  * with Klaus Bongartz, D. Mertens, A. Steins: Farbige Parkette. Mathematische Theorie und Ausführung auf dem Computer [Colored tilings: mathematical theory and computer implementation], Birkhäuser 1988
  * with Jean-Luc Brylinski, Robert MacPherson: Nilpotent orbits, primitive ideals and characteristic classes. A geometric perspective in ring theory, Birkhäuser 1989
  * with Karsten Blankenagel, Axel vom Stein: Blankenagel, Karsten; Borho, Walter; Vom Stein, Axel (2003). "New amicable four-cycles". Math. Comp. 72 (244): 2071–2076. doi:10.1090/s0025-5718-03-01489-3. MR 1986823.
  