In this study, we introduce a new class of rational elliptic 3-folds, which we refer to as "1/2 Calabi-Yau 3-folds". We construct elliptically fibered Calabi-Yau 3-folds by utilizing these rational elliptic 3-folds. The construction yields a novel approach to build elliptically fibered Calabi-Yau 3-folds of various Mordell-Weil ranks. Our construction of Calabi-Yau 3-folds can be considered as a three-dimensional generalization of the operation of gluing pairs of 1/2 K3 surfaces to yield elliptic K3 surfaces. From one to seven $U(1)$s form in six-dimensional $N=1$ F-theory on the constructed Calabi-Yau 3-folds. Seven tensor multiplets arise in these models.

中文翻译：

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12$$ \frac{1}{2} $$ Calabi-Yau 3-folds, Calabi-Yau 3-folds as double cover, F-theory with U(1)s

在这项研究中，我们引入了一类新的有理椭圆 3-folds，我们称之为“1/2 Calabi-Yau 3-folds”。我们利用这些有理椭圆 3 折构造了椭圆纤维化的 Calabi-Yau 3 折。该构造产生了一种新方法来构建各种 Mordell-Weil 等级的椭圆形纤维 Calabi-Yau 3 倍。我们对 Calabi-Yau 3-fold 的构造可以被认为是粘合 1/2 K3 表面对以产生椭圆 K3 表面的操作的三维推广。在构造的 Calabi-Yau 3-folds 上，从一到七个 $U(1)$ 形成六维 $N=1$ F 理论。在这些模型中出现了七个张量多重态。