Year: 2026
Type: article
Abstract: Tree-level open-string disk integrals obey finite-difference equations in the kinematic invariants, but these equations do not by themselves select a unique solution: they leave an arbitrary periodic matrix factor. We show that finitely many fixed-angle high-energy boundary conditions remove this functional ambiguity at any fixed multiplicity. On generic continuous kinematic rays, the periodic quotient is sampled densely, so exponentially suppressed branch mixing must vanish identically. In split-positive kinematics, the scattering equations identify the relevant high-energy branches. In one fixed, branch-labeled column frame, calibration on one ray and exponential growth bounds on finitely many permuted rays remove the nonconstant periodic ambiguity. The period matrix is then fixed up to a constant right factor, with the remaining freedom removed by any nonsingular normalization, such as the field-theory limit. Thus finite high-energy data complete the kinematic difference equations into a global uniqueness criterion for the Koba–Nielsen period matrix.
Source: Nuclear Physics B
Author: Ye Zhou (周烨)
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7221692517