SciPost logo

Evaluating one-loop string amplitudes

Lorenz Eberhardt, Sebastian Mizera

SciPost Phys. 15, 119 (2023) · published 27 September 2023


We evaluate one-loop open-string amplitudes at finite $\alpha'$ for the first time. Our method involves a deformation of the integration contour over the modular parameter $\tau$ to a fractal contour introduced by Rademacher in the context of analytic number theory. This procedure leads to explicit and practical formulas for the one-loop four-point amplitudes in type-I superstring theory, amenable to numerical evaluation. We plot the amplitudes as a function of the Mandelstam invariants $s$ and $t$ and directly verify long-standing conjectures about their behaviour at high energies.

Cited by 3

Crossref Cited-by

Authors / Affiliation: mappings to Contributors and Organizations

See all Organizations.
Funder for the research work leading to this publication