It is shown that in presence of certain external fields a well-defined self-adjoint time operator exists, satisfying the standard canonical commutation relations with the Hamiltonian. Examples include uniform electric and gravitational fields with nonrelativistic and relativistic Hamiltonians. The physical intepretation of these operators is proposed in terms of time of arrival in the momentum space.

中文翻译：

---

动量空间中的到达时间算子

结果表明，在存在某些外部场的情况下，存在明确定义的自伴时间算子，满足与哈密顿量的标准规范交换关系。例子包括具有非相对论性和相对论性哈密顿量的均匀电场和引力场。这些算子的物理解释是根据动量空间中的到达时间提出的。