Topic: unitarity

The conformal bootstrap studies strongly coupled quantum field theories through symmetry, unitarity and crossing symmetry without relying on perturbation theory. This talk reviews recent analytic functional approaches to the numerical bootstrap and introduces new results. It then considers how machine learning could navigate consistent conformal field theories. Neural networks can construct crossing-symmetric correlators from limited physical input; their tendency toward simple, smooth solutions may reveal additional organizing principles behind bootstrap constraints.

Consistency requirements on scattering amplitudes can constrain quantum gravity without a perturbative expansion. This talk applies analyticity, crossing and unitarity to maximally supersymmetric gravitational theories in ten and eleven dimensions. It extends bounds from the leading correction to higher-order effective couplings, comparing the allowed regions with string-theory and M-theory predictions. A nearby kink in eleven dimensions suggests a possible route toward characterizing the M-theory scattering matrix through consistency alone.