We examine the problem of constructing three generation free fermionic string models with grand unified gauge groups. We attempt the construction of G\times G models, where G is a grand unified group realized at level 1. This structure allows those Higgs representations to appear which are necessary to break the symmetry down to the standard model gauge group. For G=SO(10), we find only models with an even number of generations. However, for G=SU(5) we find a number of 3 generation models.
展开▼
机译：我们研究了构造具有统一大规格组的三代自由费米型弦模型的问题。我们尝试构建G \ times G模型，其中G是在级别1上实现的一个统一大组。此结构允许出现将对称性分解为标准模型量规组所必需的希格斯表示。对于G = SO（10），我们仅找到具有偶数代的模型。但是，对于G = SU（5），我们发现了许多3代模型。
展开▼
