负作用量 Keldysh 旋量
The Negative Action Keldysh Spinors
AI总结：
本文研究作用量为负的 Dirac 旋量在 Keldysh 量子场论中的量子化，证明标准量子化导致哈密顿量上界有界和时间反向散射，而替代量子化恢复下界有界的标准哈密顿量与正向散射 S 矩阵，并提出若 Keldysh 旋量存在，可解释暗能量/暗物质仅通过经典引力显现的现象。
摘要：
我们讨论作用量为标准作用量之负值的 Dirac 旋量的量子化。利用 Keldysh 量子场论表述，我们证明对此类 Keldysh 旋量进行标准量子化会导致哈密顿量上界有界，并得到时间反向散射的 S 矩阵。替代量子化则产生下界有界的标准哈密顿量以及时间正向散射的标准 S 矩阵。当两种质量相等时，它们的作用量之和描述了标准的 Keldysh 非时序关联函数。当一个量子场论中同时存在 Keldysh 旋量和 Dirac 旋量时，标准 Fock 空间会被负能量态扩充，而其正、负子空间共享同一个真空态。在没有引力的情况下，Dirac 旋量与 Keldysh 旋量不发生相互作用，正能量态和负能量态不会交换非零能量量子。如果 Keldysh 旋量在自然界中存在，那么宇宙将由玻色子和费米子粒子组成，这些粒子同时由正能量和负能量 Fock 态描述，且只有一个无法从任何一侧穿越的真空态。这种情形可以解释暗能量/暗物质除通过经典引力外未被观测到的现象。
英文摘要：
We discuss quantization of Dirac spinors with action which is the negative of the standard action. Using the Keldysh QFT formulation, we show that the standard quantization of such Keldysh spinors results in the Hamiltonian bounded from above and in S-matrix for backwards in time scattering. The alternative quantization produces the standard Hamiltonian bounded from below and the standard S-matrix for forwards in time scattering. When the two masses are equal, the sum of their actions describes the standard Keldysh out-of-time-order correlators. When both Keldysh and Dirac spinors are present in a QFT, the standard Fock space is augmented by negative energy states, while its positive and the negative subspaces share the same vacuum state. In absence of gravity the Dirac and the Keldysh spinors do not interact and positive and negative energy states do not exchange quanta with non-zero energy. If Keldysh spinors exist in Nature, then the Universe would consist of bosonic and fermionic particles that are described by both positive and negative Fock energy states with a single vacuum state that cannot be crossed from either side. Such a scenario could explain the non-observation of dark energy/dark matter except via classical gravity.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
