Mass eigenstates in bimetric theory with matter coupling
Mass eigenstates in bimetric theory with matter coupling
复制标题
物质耦合双计量理论中的质量本征态
DOI：
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发表时间：
2014
期刊：
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通讯作者：
A. Schmidt
中科院分区：
文献类型：
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作者：
A. Schmidt
在本文中，我们研究了最近提出的通过复合度规耦合到物质的无幽灵的双度规作用量。该理论的运动方程是使用一种避免改变物质耦合中出现的平方根矩阵的方法导出的。我们做了一个度量成比例的矩阵，发现只要动作中的一个参数是固定的，它就能解方程。在这种情况下，比例度规以及耦合到物质的有效度规解决了爱因斯坦的广义相对论方程，包括物质源。围绕这些背景，我们推导出微扰的二次作用量，并将其对角化为广义质量本征态。结果表明，物质只与无质量自旋2模相互作用，其运动方程具有线性化爱因斯坦方程的形式，而具有Fierz-Pauli质量项的场是完全解耦的。因此，双度量理论，与一个参数固定，使比例的解决方案存在，是退化与广义相对论的线性秩序周围的这些背景。
In this paper we study the ghost-free bimetric action extended by a recently proposed coupling to matter through a composite metric. The equations of motion for this theory are derived using a method which avoids varying the square-root matrix that appears in the matter coupling. We make an ansatz for which the metrics are proportional to each other and find that it can solve the equations provided that one parameter in the action is fixed. In this case, the proportional metrics as well as the effective metric that couples to matter solve Einstein's equations of general relativity including a matter source. Around these backgrounds we derive the quadratic action for perturbations and diagonalize it into generalized mass eigenstates. It turns out that matter only interacts with the massless spin-2 mode whose equation of motion has exactly the form of the linearized Einstein equations, while the field with Fierz-Pauli mass term is completely decoupled. Hence, bimetric theory, with one parameter fixed such that proportional solutions exist, is degenerate with general relativity up to linear order around these backgrounds.