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arXiv · 1811.02548

Heterotic-string amplitudes at one loop: modular graph forms and relations to open strings

Jan E. Gerken·Axel Kleinschmidt·Oliver Schlotterer
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Abstract

We investigate one-loop four-point scattering of non-abelian gauge bosons in heterotic string theory and identify new connections with the corresponding open-string amplitude. In the low-energy expansion of the heterotic-string amplitude, the integrals over torus punctures are systematically evaluated in terms of modular graph forms, certain non-holomorphic modular forms. For a specific torus integral, the modular graph forms in the low-energy expansion are related to the elliptic multiple zeta values from the analogous open-string integrations over cylinder boundaries. The detailed correspondence between these modular graph forms and elliptic multiple zeta values supports a recent proposal for an elliptic generalization of the single-valued map at genus zero.

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Jan E. Gerken, Axel Kleinschmidt, Oliver Schlotterer. 2018-11-06. Heterotic-string amplitudes at one loop: modular graph forms and relations to open strings. https://doi.org/10.1007/jhep01(2019)052

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