TITLE: What are "Artin fractions"?
QUESTION [10 upvotes]: The German Wikipedia entry for Ernst Witt https://de.wikipedia.org/wiki/Ernst_Witt has a photo of his grave in Hamburg. The bottom part has a visible text "Artin Brueche" (Artin fractions) but the numbers are obscured.
Does anyone know what the numbers are, why they are called Artin fractions, and why Witt wanted to have them on his gravestone.

REPLY [5 votes]: I have the impression that this "Artin fraction" is the Artin symbol, introduced by Helmut Hasse. Both Hasse and Emil Artin were teachers of Ernst Witt.
The inscription higher up on the grave stone shows a Witt vector, perhaps in reference to the Artin-Schreier-Witt theory. My guess would be that the inscription at the bottom explains the notation of the formula above it. Perhaps someone in the vicinity of Hamburg can make a trip to the cemetery and provide a full exposure of the grave stone?