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arXiv · 2502.20372

Positivity of the Veneziano Amplitude in Ten Dimensions

Abstract

The Veneziano amplitude describing the tree-level scattering of four open superstrings is expected to be consistent with unitarity in ten spacetime dimensions. While this follows indirectly from the no-ghost theorem, a direct proof at the level of the amplitude has only been found for $D\leq 6$. In this article, we close this gap by providing a complete proof for the partial-wave positivity of the Veneziano amplitude in $D\leq 10$, derived directly from its definition in terms of the Euler beta function. We also demonstrate that this proof can be modified to show positivity of a wider family of amplitudes relevant to the $S$-matrix bootstrap.

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BibTeXRIS

Gareth Mansfield. 2026-02-17. Positivity of the Veneziano Amplitude in Ten Dimensions. https://arxiv.org/abs/2502.20372

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