Heterotic string plus five-brane systems with asymptotic $\mathrm{AdS}_3$

Abstract

>We present $NS1+NS5$-brane solutions of heterotic supergravity on curved geometries. They interpolate between a near horizon $\mathrm{AdS}_3 \times X^k \times \mathbb{T}^{7-k}$ region and $\mathbb R^{1,1} \times c(X^k) \times \mathbb{T}^{7-k}$, where $X^k$ (with $k =3,5,6,7$) is a $k$-dimensional geometric Killing spinor manifold, $c(X^k)$, its Ricci-flat cone and $\mathbb{T}^{7-k}$ a $(7-k)$-torus. The solutions require first-order $\alpha'$-corrections to the field equations, and special point-like instantons play an important role, whose singular support is a calibrated submanifold wrapped by the $\mathrm{NS5}$-brane. It is also possible to add a gauge anti-five-brane. We determine the super isometries of the near horizon geometry, which are supposed to appear as symmetries of the holographically dual two-dimensional conformal field theory.