Speaker
Description
We present an exact four-parameter rotating vacuum solution of the pure NS--NS sector, or equivalently of Double Field Theory. The solution is generated by applying a compact (\mathrm{SO}(2)) (S)-duality transformation to a rotating Einstein--scalar seed and is specified by ({m,j,q,\zeta}). It gives analytic expressions for the metric, Kalb--Ramond field, and dilaton, with independent dilaton and (H)-flux charges and without introducing a Maxwell sector. In the non-rotating limit (j\to 0), the geometry does not reduce to the spherical Burgess--Myers--Quevedo branch, but instead to an axial Zipoy--Voorhees branch carrying (H)-flux. Thus an oblate deformation survives after rotation is removed. Although the two static branches agree in their monopole PPN data, their degeneracy is lifted at quadrupole order. The Kerr-shell locus is generically curvature singular, while above a charge threshold polar geodesics are repelled and the rotation axis develops a localized degeneracy suggestive of a non-Riemannian Double Field Theory description.
