I will present a joint work with A. Connes on an integral, absolute Riemann-Roch formula for the number field Q. Central to this, is the characterization of the integers as a polynomial ring S[X] over the absolute base, subject to the relation $1+1=X+X^2$.

Bio: Caterina (Katia) Consani is an Italian/US mathematician. Consani earned a doctorate from the University of Turin (and Genoa) in 1993 and a Ph.D. from the University of Chicago in 1996, under the supervision of Spencer Bloch. She then held a Moore Instructorship at MIT, and an assistant-associate professorship at the University of Toronto. Since 2008 she holds a professorship at Johns Hopkins University. Her research is in arithmetic-noncommutative geometry. She is a fellow of the American Mathematical Society.