Effective action of type II superstring theories at order α′3: NS-NS couplings

Recently, it has been shown that the minimum number of gauge invariant couplings for $B$-field, metric and dilaton at order $\alpha'^3$ is 872. These couplings, in a particular scheme, appear 55 different structures. In this paper, up to an overall factor, we fix all parameters type II supertirng theories by requiring reduction on circle be under T-duality transformations. We find there are 445 non-zero which 15 The fully consistent with partial have found literature four-point S-matrix element non-linear Sigma model methods.