Carving out the space of open-string S-matrix

A bstract In this paper, we explore the open string amplitude’s dual role as a space-time S-matrix and 2D holomorphic CFT correlation function. We pursue correspondence in two directions. First, beginning with general disk integrand dressed Koba-Nielsen factor, demonstrate that exchange symmetry for factorization residue of amplitude forces to be expandable on SL(2,R) conformal blocks. Furthermore, positivity constraints associated unitarity imply blocks must come linear combinations which Virasoro block emerges at “kink” space solutions. other words, arises boundary consistent factorization. Next, consider low energy EFT description, where manifests EFThedron couplings live. The existence worldsheet description implies, through monodromy relations impose algebraic identities amongst couplings. finite derivative order intersection “monodromy plane” four-dimensional carves out tiny island couplings, continues shrink is increased. At eighth order, three-dimensional plane, fixes width around 1.5% (of ? (3)) 0.2% (5)) respect toroidally compactified Type-I super answer. This leads us conjecture four-point superstring can completely determined by geometry plane EFThedron.