arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv gr-qc/0209022gr-qchep-th
收藏

高阶导数引力产生的非线性质量自旋二场

Nonlinear massive spin-two field generated by higher derivative gravity

G. Magnano, L. M. Sokolowski

摘要:

本文系统地阐述了在高导数引力场中产生的大质量自旋二场的拉格朗日场论。不同的作者已经注意到,这种非线性场克服了与爱因斯坦引力相互作用的线性大质量自旋2场理论的众所周知的不一致性。本文从一个二次依赖于度规的Ricci张量的拉格朗日量出发,讨论了通常称为“(Helmholtz)Jordan标架”和“Einstein标架”的两种可能的二阶图像。尽管它们在数学上是等价的,但这两个框架具有不同的结构性质:在爱因斯坦框架中,自旋为2的场与引力的耦合最小,而在另一个框架中,它必然与曲率耦合,没有单独的动力学项。我们证明了该理论承认一个唯一的和线性稳定的基态解,并且运动方程是一致的,表明这些结果可以在任一框架中独立地得到。本文给出了自旋2场在Einstein框架中的完整运动方程和能量动量张量,并求出了这些方程的一个简单而非平凡的精确解.两个框架中自旋2场的能量动量张量的比较表明,Einstein框架在物理上更可取.我们指出,由线性化理论的拉格朗日量产生的能量动量张量与完整理论的相应张量无关。然后,有人认为,幽灵般的性质的非线性自旋2场,发现很久以前的线性近似,可能不会那么有害的经典稳定性问题,因为已经预期。

英文摘要:

We present a systematic exposition of the Lagrangian field theory for the massive spin-two field generated in higher-derivative gravity. It has been noticed by various authors that this nonlinear field overcomes the well known inconsistency of the theory for a linear massive spin-two field interacting with Einstein's gravity. Starting from a Lagrangian quadratically depending on the Ricci tensor of the metric, we explore the two possible second-order pictures usually called "(Helmholtz-)Jordan frame" and "Einstein frame". In spite of their mathematical equivalence, the two frames have different structural properties: in Einstein frame, the spin-two field is minimally coupled to gravity, while in the other frame it is necessarily coupled to the curvature, without a separate kinetic term. We prove that the theory admits a unique and linearly stable ground state solution, and that the equations of motion are consistent, showing that these results can be obtained independently in either frame. The full equations of motion and the energy-momentum tensor for the spin--two field in Einstein frame are given, and a simple but nontrivial exact solution to these equations is found. The comparison of the energy-momentum tensors for the spin-two field in the two frames suggests that the Einstein frame is physically more acceptable. We point out that the energy-momentum tensor generated by the Lagrangian of the linearized theory is unrelated to the corresponding tensor of the full theory. It is then argued that the ghost-like nature of the nonlinear spin-two field, found long ago in the linear approximation, may not be so harmful to classical stability issues, as has been expected.

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。

↑