Buscher dilaton shift
= Buscher dilaton shift
{c}
{title2=$\varphi'=\varphi-\frac12\log g_{yy}$}
The quantum measure in abelian <T-duality> changes the conventional <dilaton> by $\varphi'=\varphi-\frac12\log g_{yy}$ in alpha-prime-one units for a spacelike isometry. The regulated Gaussian integration over the auxiliary gauge field produces this curvature coupling. It is consistent with invariance of the string-frame density $e^{-2\varphi}\sqrt{\det g}$ under the local Buscher rules.