We show that the maximal frequency of cosmic gravitons must not exceed the THz domain. From a classical viewpoint, both in conventional inflationary scenarios and in bouncing models the largest frequency of the spectrum overshoots the MHz band even if its specific signature is model dependent. According to a quantum mechanical perspective the maximal frequency is instead associated with the range of energies where a single pair of gravitons with opposite (comoving) three-momenta is produced. The upper limit on the largest frequency determines the minimal chirp amplitude [typically ] required for a direct detection of a cosmic signal in the THz band. Below this limiting frequency the minimal chirp amplitude can be enhanced so that the optimal range ultimately depends on the physical properties of the diffuse backgrounds. In case a hypothetical instrument (at present just a figment of a hopeful imagination) would reach chirp amplitudes down to in the MHz or GHz bands, the Bose-Einstein correlations could be used to probe the properties of cosmic gravitons and their super-Poissonian statistics.

中文翻译：

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宇宙引力子的最大频率


我们证明宇宙引力子的最大频率不得超过太赫兹域。从经典的角度来看，无论是在传统的通货膨胀场景还是在弹跳模型中，频谱的最大频率都会超过 MHz 频段，即使其特定特征取决于模型。根据量子力学的观点，最大频率与产生具有相反（共动）三动量的一对引力子的能量范围相关。最大频率的上限决定了直接检测太赫兹频段宇宙信号所需的最小线性调频幅度（通常）。低于该限制频率，可以增强最小线性调频幅度，以便最佳范围最终取决于漫射背景的物理特性。如果假设的仪器（目前只是充满希望的想象）能够达到 MHz 或 GHz 频段的啁啾幅度，玻色-爱因斯坦相关性可用于探测宇宙引力子的特性及其超泊松统计。