We use compatibility of O-plane action with nonlinear T-duality as a guiding principle to find all NS-NS couplings in the O-plane action at order $\\alpha'^2$. We find that the dilaton couplings appear in the string frame only via...

of two $R^4$ terms become identical. The Riemann curvature couplings that the T-duality constraint produces for both type II and Heterotic theories are fully consistent with the existing couplings in the literature which have been found by the S...

Using the compatibility of the DBI and the Chern-Simons actions with the T-duality transformations, we extend the curvature corrections to these actions to include the quadratic B-field couplings at order O( alpha ^2) . We then use...

Recently it has been speculated that the S-matrix elements satisfy the Ward identity associated with the T-duality. This indicates that a group of S-matrix elements is invariant under the linear T-duality transformations on the external...

We examine the sigma model Riemann curvature corrections to the supergravity action under

T-duality transformations. Using the compatibility of the effective action with on-shell linear T-duality and with the S-matrix calculations...

We examine the NS-NS corrections to the type II supergravity given by Gross and Sloan, under the linear T-duality transformations. We show that the gravity and the B-field couplings are invariant under off-shell T-duality, whereas the dilaton...

By explicit calculations of four-field couplings, we observe that the higher derivative corrections to the DBI action in flat space-time, can be either in a covariant form or in a T-duality invariant form. The two forms are related by a non...

It is known that the anomalous D$_p$-brane Chern-Simons couplings are not consistent with the standard rules of T-duality. Using compatibility of these couplings with the linear T-duality transformations, the B-field gauge transformations...

and one NS fields with unknown coefficients. We then constrain the couplings to be consistent with the linear T-duality and with the above contact terms. Interestingly, we have found that up to total derivative terms and Bianchi identities...

We examine the proposal that the dimensional reduction of the effective action of perturbative string
theory on a circle should be invariant under T-duality transformations. The T-duality transformations are
the standard Buscher rules plus...