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arXiv 0805.0486gr-qc
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弯曲背景下的引力波:de Sitter时空中的一致性分析

Gravitational waves about curved backgrounds: a consistency analysis in de Sitter spacetime

Donato Bini, Salvatore Capozziello, Giampiero Esposito

摘要:

引力波被认为是关于弯曲背景度规的度规扰动,而不是平坦的闵可夫斯基度规,因为通过这种推广可以讨论物理上感兴趣的几种情况。在这种情况下,当施加de Donder规范时,它在无穷小时空同态下的保持是保证的,当且仅当相关的余向量由二阶双曲算子支配,这是量子引力中鬼算子的经典对应物。在这样的波动方程中,里奇项与洛伦兹规范中麦克斯韦理论的波动方程符号相反。然而,我们能够将这两个问题的解决方案联系起来,并且该算法适用于弯曲背景几何是德西特时空的情况。这样的矢量波方程研究在两个不同的方式:i)积分表示,ii)通过双曲方程的因式分解的解决方案。后一种方法被推广到de Sitter时空中的度规扰动波动方程。这种方法是对德西特时空中的引力波进行一般性讨论的一步,并且可能与宇宙学相关,以便研究暴胀产生的随机背景。

英文摘要:

Gravitational waves are considered as metric perturbations about a curved background metric, rather than the flat Minkowski metric since several situations of physical interest can be discussed by this generalization. In this case, when the de Donder gauge is imposed, its preservation under infinitesimal spacetime diffeomorphisms is guaranteed if and only if the associated covector is ruled by a second-order hyperbolic operator which is the classical counterpart of the ghost operator in quantum gravity. In such a wave equation, the Ricci term has opposite sign with respect to the wave equation for Maxwell theory in the Lorenz gauge. We are, nevertheless, able to relate the solutions of the two problems, and the algorithm is applied to the case when the curved background geometry is the de Sitter spacetime. Such vector wave equations are studied in two different ways: i) an integral representation, ii) through a solution by factorization of the hyperbolic equation. The latter method is extended to the wave equation of metric perturbations in the de Sitter spacetime. This approach is a step towards a general discussion of gravitational waves in the de Sitter spacetime and might assume relevance in cosmology in order to study the stochastic background emerging from inflation.

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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