标题： 弦紧致化的新的分支及其F理论对偶 显示英文标题

标题： New Branches of String Compactifications and their F-Theory Duals

摘要： 我们研究了异质的 $E_8\times E_8$ 模型，这些模型与 F 理论和类型 IIA 弦在某些椭圆纤维化的卡拉比-丘流形上的紧化是对偶的。 纤维化中特定环面的不同选择具有异质对偶性，这些对偶最易于用 $E_8\times E_8$ 模型中的规范背景来理解，其中 $H\times U(1)^{8-d}$ 是非交换因子 $H$。 具有$d=8$的情形对应于著名的$E_8\times E_8$紧化，这些紧化具有非阿贝尔瞬子背景$(k_1,k_2)$，其 F 理论对偶是通过在 torus$\IP_2^{(1,2,3)}[6]$上的纤维化紧化$\IF_n$构造的。 具有$d < 8$的新情形对应于相同基底上椭圆纤维的其他选择，产生未破缺的$U(1)$，其中一些是反常的，并通过吞噬反对称场$B_{MN}$的零模而获得质量。 我们还研究了$D=6$中无张量多重态模型的转变，并发现了$E_d$瞬子动力学的证据。 我们还考虑了具有不同椭圆纤维实现的空间之间的锥形变换的可能性。 显示英文摘要

摘要： We study heterotic $E_8\times E_8$ models that are dual to compactifications of F-theory and type IIA string on certain classes of elliptically fibered Calabi-Yau manifolds. Different choices for the specific torus in the fibration have heterotic duals that are most easily understood in terms of $E_8\times E_8$ models with gauge backgrounds of type $H\times U(1)^{8-d}$, where $H$ is a non-Abelian factor. The case with $d=8$ corresponds to the well known $E_8\times E_8$ compactifications with non-Abelian instanton backgrounds $(k_1,k_2)$ whose F-theory duals are built through compactifications on fibrations of the torus $\IP_2^{(1,2,3)}[6]$ over $\IF_n$. The new cases with $d < 8$ correspond to other choices for the elliptic fiber over the same base and yield unbroken $U(1)$'s, some of which are anomalous and acquire a mass by swallowing zero modes of the antisymmetric $B_{MN}$ field. We also study transitions to models with no tensor multiplets in $D=6$ and find evidence of $E_d$ instanton dynamics. We also consider the possibility of conifold transitions among spaces with different realization of the elliptic fiber.