Scharlau's research deals with number theory and, in particular, the theory of quadratic forms, about which he wrote a 1985 monograph Quadratic and Hermitian Forms in Springer's series Grundlehren der mathematischen Wissenschaften.[4][5]
Scharlau was also an amateur ornithologist and author of two novels, I megali istoria - die große Geschichte (2nd edition 2001), set on the Greek island of Naxos, and Scharife (2001), set on the island of Zanzibar in the 19th century.[6] He also deals with the history of mathematics and wrote, with Hans Opolka,[7] a historically-oriented introduction to number theory. Their book presents, among other topics, the analytical class number formula of Dirichlet and the geometry of the numbers in the 19th century.[8] Scharlau wrote a multi-part biography of Alexander Grothendieck.[6]
Mathematik für Naturwissenschaftler. LIT Verlag, Münster 2005
Winfried Scharlau (2011), Wer ist Alexander Grothendieck? Anarchie, Mathematik, Spiritualität, Einsamkeit (in German), vol. Teil 1. Anarchie (3. ed.), Norderstedt: Books on Demand, ISBN978-3-8423-7147-7
Winfried Scharlau (2010), Wer ist Alexander Grothendieck? Anarchie, Mathematik, Spiritualität, Einsamkeit (in German), vol. Teil 3. Spiritualität, Norderstedt: Books on Demand, ISBN978-3-8391-4939-3
Winfried Scharlau (2016), Das Glück, Mathematiker zu sein. Friedrich Hirzebruch und seine Zeit (in German), Wiesbaden: Springer Spektrum, ISBN978-3-658-14756-3