arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2007.00138nucl-thhep-phhep-th
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自旋张量和赝规范:从核碰撞到引力物理

Spin tensor and pseudo-gauges: from nuclear collisions to gravitational physics

Enrico Speranza, Nora Weickgenannt

摘要:

自旋的相对论处理是一个历史悠久的基础性课题。在不同的物理背景下,有必要将相对论性的总角动量分成轨道和自旋的贡献。然而,这样的分解会受到模糊性的影响,因为人们总是可以通过所谓的伪规范变换来重新定义轨道和自旋部分。我们详细分析了这个问题,讨论了最常见的选择的能量动量和自旋张量,强调其物理含义,并研究了自旋矢量,这是一个伪规范不变的操作。我们回顾角动量分解的相对论自旋流体力学和量子动力学理论的制定的一个重要组成部分,专注于相对论核碰撞,自旋物理最近引起了极大的关注。此外,我们还指出了赝规范变换与相对论性质心不同定义之间的联系。最后,我们考虑爱因斯坦-嘉当理论,传统的广义相对论的扩展,它允许一个自然的定义的自旋张量。

英文摘要:

The relativistic treatment of spin is a fundamental subject which has an old history. In various physical contexts it is necessary to separate the relativistic total angular momentum into an orbital and spin contribution. However, such decomposition is affected by ambiguities since one can always redefine the orbital and spin part through the so-called pseudo-gauge transformations. We analyze this problem in detail by discussing the most common choices of energy-momentum and spin tensors with an emphasis on their physical implications, and study the spin vector which is a pseudo-gauge invariant operator. We review the angular momentum decomposition as a crucial ingredient for the formulation of relativistic spin hydrodynamics and quantum kinetic theory with a focus on relativistic nuclear collisions, where spin physics has recently attracted significant attention. Furthermore, we point out the connection between pseudo-gauge transformations and the different definitions of the relativistic center of mass. Finally, we consider the Einstein-Cartan theory, an extension of conventional general relativity, which allows for a natural definition of the spin tensor.

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。

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