Massless positivity in graviton exchange
Massless positivity in graviton exchange
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引力子交换中的无质量正性
作者：
M. Herrero;Raquel Santos;A. Tokareva
我们给出了包含无质量粒子交换的散射振幅的正界。我们通过色散关系将标准构造推广到包含Maldestam变量$s$在复平面上沿实轴的分支切割的存在。一般来说，这些边界的有效性需要消去与$t^{-1}$和$\log(t)$成比例的振幅前极限的散度。我们证明，在重子的情况下，如果假设在普朗克尺度以下的高能量下振幅具有雷格行为，这是可能的，正如先前在文献中提出的那样。我们在这里提出的边界有可能约束非常一般的修正引力模型和物质与引力耦合的eft。
We formulate Positivity Bounds for scattering amplitudes including exchange of massless particles. We generalize the standard construction through dispersion relations to include the presence of a branch cut along the real axis in the complex plane for the Maldestam variable $s$. In general, validity of these bounds require the cancellation of divergences in the forward limit of the amplitude, proportional to $t^{-1}$ and $\log(t)$. We show that this is possible in the case of gravitons if one assumes a Regge behavior of the amplitude at high energies below the Planck scale, as previously suggested in the literature. The bounds that we present here have the potential of constraining very general models of modified gravity and EFTs of matter coupled to gravitation.