The reeason is not

… that Alfred Nobel’s wife (sometimes mistress or fiancée) had an affair with a famed mathematics professor (actual name of professor varies based on who’s telling the story, but most popular go with famed Swedish mathematician Gosta Mittag-Leffler). So Nobel stipulated in his will that there should not be a Nobel Prize for mathematics for fear that said famed mathematics professor would win it (which was all but a certainty had there been a Nobel Prize for mathematics).

The Reason There is No “Nobel Prize for Mathematics” Had Nothing to Do With Any Wife/Mistress of Alfred Nobel.