Some relevant links on Jorge Luis Borges and Mathematics:

Unthinking Thinking: Jorge Luis Borges, Mathematics and the New Physics by Floyd Merrell (Purdue University Press, 1991);

The Unimaginable Mathematics of Borges' Library of Babel by William Goldbloom Bloch (Oxford University Press, 2008);

From Borges y la matemática by Guillermo Martínez (Buenos Aires: Seix Barral, 2007).