22,996 research outputs found
T-duality of -correction to DBI action at all orders of gauge field
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-covariant field redefinition. Using this observation, we then propose a
non-covariant but T-duality invariant action which includes all orders of
massless fields and has two extra derivatives with respect to the DBI action.Comment: 16 pages, latex file, no figure; v3:minor modification, it appears in
NP
S-duality constraint on higher-derivative couplings
The Riemann curvature correction to the type II supergravity at
eight-derivative level in string frame is given as
e^{-2\phi}(t_8t_8R^4+\frac{1}{4}\eps_{8}\eps_{8}R^4). For constant dilaton, it
has been extended in the literature to the S-duality invariant form by
extending the dilaton factor in the Einstein frame to the non-holomorphic
Eisenstein series. For non-constant dilaton, however, there are various
couplings in the Einstein frame which are not consistent with the S-duality. By
constructing the tensors from Born-Infeld action, we include the
appropriate Ricci and scalar curvatures as well as the dilaton couplings to
make the above action to be consistent with the S-duality.Comment: 23 pages, Latex file, no figure; v3:some typos correcte
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