O(n, n) invariance and Wald entropy formula in the Heterotic Superstring effective action at first order in α′

We perform the toroidal compactification of the full Bergshoeff-de Roo version of the Heterotic Superstring effective action to first order in alpha '. The dimensionally-reduced action is given in a manifestly-O(n, n)-invariant form which we use to derive a manifestly-O(n, n)-invariant Wald entropy formula which we then use to compute the entropy of alpha ' -corrected, 4-dimensional, 4-charge, static, extremal, supersymmetric black holes.

Automated summary

In this study, the toroidal compactification of the Bergshoeff-de Roo version of the Heterotic Superstring effective action to first order in alpha ' was performed. The dimensionally-reduced action was then utilized to derive a manifestly-O(n, n)-invariant Wald entropy formula, which was applied to calculate the entropy of alpha ' -corrected, 4-dimensional, 4-charge, static, extremal, supersymmetric black holes.