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arXiv · 2309.14440

Hypermultiplet metric and NS5-instantons

Sergei Alexandrov·Khalil Bendriss
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Abstract

The metric on the hypermultiplet moduli space of Calabi-Yau compactifications of type II string theory is known to receive D-brane and NS5-brane instanton corrections. We compute explicit expressions for these corrections in the one-instanton approximation, but to all orders in the string coupling expansion around the instantons. As a consistency check, we prove that in the case of one (universal) hypermultiplet, the resulting metric fits the Przanowski description of self-dual Einstein spaces. We also show that in the small string coupling limit the metric acquires a certain square structure, consistently with expectations from the string amplitudes analysis. This result provides explicit predictions for yet mysterious string amplitudes in the presence of NS5-branes.

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Sergei Alexandrov, Khalil Bendriss. 2023-09-25. Hypermultiplet metric and NS5-instantons. https://doi.org/10.1007/jhep01(2024)140

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