标题： 关于量子理论中相互作用的问题 显示英文标题

标题： On the problem of interactions in quantum theory

摘要： 研究了在具有不变性群SO(1,4)的理论中描述自由粒子系统的表示结构。 粒子的自由性质通常意味着描述多粒子系统的表示是相应单粒子表示的张量积（即，不引入相互作用）。 结果表明，质量算符仅在区间$(-\infty,\infty)$内包含连续谱，这样的表示与描述相互作用（引力、电磁等）的表示是酉等价的。 这意味着该理论中不存在束缚态，多粒子系统的希尔伯特空间包含一个子空间，其状态具有如下性质：自由表示算子在这些状态上的作用表现为不同的相互作用。 讨论了结果可能带来的后果。 显示英文摘要

摘要： The structure of representations describing systems of free particles in the theory with the invariance group SO(1,4) is investigated. The property of the particles to be free means as usual that the representation describing a many-particle system is the tensor product of the corresponding single-particle representations (i.e. no interaction is introduced). It is shown that the mass operator contains only continuous spectrum in the interval $(-\infty,\infty)$ and such representations are unitarily equivalent to ones describing interactions (gravitational, electromagnetic etc.). This means that there are no bound states in the theory and the Hilbert space of the many-particle system contains a subspace of states with the following property: the action of free representation operators on these states is manifested in the form of different interactions. Possible consequences of the results are discussed.