Sun and Ma (2013, 2019) proved the existence of nonzero $T$-periodic solution for the Fermi–Pasta–Ulam (FPU) lattice dynamical system. In this paper, we prove the existence of ground state solutions, i.e., the least energy of nonzero $T$-periodic solution for FPU lattice dynamical systems via Non-Nehari method developed recently by Tang et al. (2020) without strict monotonous condition.

中文翻译：

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FPU格不定情况下的晶格动力系统的周期运动。

Sun and Ma（2013，2019）证明了非零的存在 $Ť$Fermi–Pasta–Ulam（FPU）晶格动力学系统的周期解。在本文中，我们证明了基态解的存在，即最小非零能量$Ť$Tang等人最近通过Non-Nehari方法开发的FPU晶格动力系统的周期解。（2020）没有严格单调的条件。