Sagnotti earned a Laurea in Electrical Engineering from the University of Rome "La Sapienza" in 1978 (advisors: Bruno Crosignani and Paolo Di Porto); and a Ph.D. in Theoretical Physics from Caltech in 1983 (advisor: John H. Schwarz). He was Post-Doctoral Fellow at Caltech (1983–84) and Miller Research Fellow at U.C. Berkeley (1984–86).[citation needed]
Sagnotti's main contribution to physics is perhaps the analysis of the 2-loop divergences in Einstein's theory of General Relativity.[1][2] Moreover, he was the first to propose, in 1987, that the type I string theory can be obtained as an orientifold of type IIB string theory,[3] with 32 half-D9-branes added in the vacuum to cancel various anomalies[4][5] and offered the elucidation of the key properties of orientifold constructions and of Conformal Field Theory on non-orientable surfaces.[6][7][8][9][10] He also discovered the 10D "0B' string", including both open and closed strings, non supersymmetric but free of tachyons.[11][12] He has worked extensively on higher spins, arriving at a geometric formulation of their free field equations in terms of higher-spin curvatures.[13]
More recently, Sagnotti has been working on the proposal of a possible link between "brane supersymmetry breaking",[14][15][16][17] and the onset of the inflationary phase, and on the exploration of some of its possible imprints on the CMB,[18] in particular, the proposal that the low value of the CMB quadrupole[19] and a first peak for l ~5[20] be a manifestation of the onset of the inflationary phase.
String Theory, eds. C. Procesi and A. Sagnotti (Academic Press, 1988)
String Theory, Quantum Gravity and the Unification of the Fundamental Interactions, eds. M. Bianchi, F. Fucito, V. Marinari and A. Sagnotti (World Scientific, 1992)
Classical and Quantum Statistical Physics, by C. Heissenberg and A. Sagnotti (Cambridge Univ. Press, 2022)