Quantum Correction and the Moduli Spaces of Calabi-Yau Manifolds
  We define the quantum correction of the Teichm\"uller space $\mathcal{T}$ of Calabi-Yau manifolds. Under the assumption of no weak quantum correction, we prove that the Teichm\"uller space $\mathcal{T}$ is a locally symmetric space with the Weil-Petersson metric. For Calabi-Yau threefolds, we show that no strong quantum correction is equivalent to that, with the Hodge metric, the image $ \Phi(\mathcal{T})$ of the Teichm\"uller space $\mathcal{T}$ under the period map $\Phi$ is an open submanifold of a globally Hermitian symmetric space $W$ of the same dimension as $\mathcal{T}$. Finally, for Hyperk\"ahler manifold of dimension $2n \geq 4$, we find both locally and globally defined families of $(2,0)$ and $(2n,0)$-classes over the Teichm\"uller space of polarized Hyperk\"ahler manifolds. 
Kefeng Liu, Changyong Yin
math.DG