Unitary bound of supergravity and symmetric points

par Dr Guillaume Bossard (CPHT, Ecole Polytechnique)

jeudi 5 oct. 2023, 11:00 → 12:00 Europe/Paris

Petit Amphi (LAPTh)

Superstring theory provides examples of consistent scattering theories of quantum gravity. One may wonder if all consistent scattering theories of quantum gravity can be realised as string theories. The landscape of string theories is yet largely unknown, so one may first restrict this question to supergravity theories with extended supersymmetry. There is a unique string theory with maximal supersymmetry in dimension lower than nine, and one expects that it is the unique ultra-violet completion of maximal supergravity. The S-matrix bootstrap provides a new tool to test this conjecture. Some recent results seem to confirm that all maximal supergravity amplitudes can be defined from string theory in dimension 10 and 9. I will report on some new results in this direction in lower dimensions. To solve this problem it is important to determine the minimum value of the leading Wilson coefficient. This minimum can be obtained at a special point of moduli space with maximal discrete symmetry.