Saturating unitarity bounds at U-duality symmetric points

Abstract

It has recently been shown that the leading Wilson coefficient in type II string theory can take (almost) all values allowed by unitarity, crossing symmetry and maximal supersymmetry in D=10 and D=9 dimensions. This suggests that string theory might define the unique consistent quantum theory of gravity with maximal supersymmetry. We study the minima of the leading Wilson coefficient in D=6, 7 and 8 dimensions and find the global minimum at the point in moduli space with maximal symmetry. The minimum value turns out to always be negative for D<8.

Misprints corrected

References in corpus (32)

• Unity of Superstring Dualities
• The Swampland: Introduction and Review
• Eleven Dimensional Origin of String/String Duality: A One Loop Test
• Effects of D-instantons
• Five-Brane Effective Action In M-Theory
• Supersymmetry Constraints on Type IIB Supergravity
• On $R^4$ threshold corrections in IIB string theory and (p,q) string instantons
• Duality and higher derivative terms in M theory
• D-instantons, Strings and M-theory
• The low energy expansion of the one-loop type II superstring amplitude
• Low energy expansion of the four-particle genus-one amplitude in type II superstring theory
• The S-matrix Bootstrap II: Two Dimensional Amplitudes
• Automorphic properties of low energy string amplitudes in various dimensions
• Causality constraints on corrections to Einstein gravity
• Where is String Theory?
• String theory dualities and supergravity divergences
• Eisenstein Series and String Thresholds
• On Brillouin Zones
• Branes and the Swampland
• Minimal representations, spherical vectors, and exceptional theta series I
• $R^4$ couplings and automorphic unipotent representations
• A note on non-perturbative R^4 couplings
• Small representations, string instantons, and Fourier modes of Eisenstein series (with an appendix by D. Ciubotaru and P. Trapa)
• Flux Tube S-matrix Bootstrap
• Modular properties of two-loop maximal supergravity and connections with string theory
• Construction of $R^4$ Terms in N=2 D=8 Superspace
• Minimal unitary representations from supersymmetry
• Where is M-theory in the space of scattering amplitudes?
• The two D6R4 type invariants and their higher order generalisation
• Massive Boson-Fermion Degeneracy and the Early Structure of the Universe
• Recursion Relations from Space-time Supersymmetry
• Supergravity divergences, supersymmetry and automorphic forms