Gibbons and Hawking (Phys. Rev. D, 15 (1977) 2738) have shown that the horizon of de Sitter space emits radiation in the same way as the event horizon of the black hole. But actual cosmological horizons are not event horizons, except in de Sitter space. Nevertheless, this paper proves Gibbons' and Hawking's radiation formula as an exact result for any flat space expanding with strictly positive Hubble parameter. The paper gives visual and intuitive insight into why this is the case. The paper also indicates how cosmological horizons are related to the dynamical Casimir effect, which makes experimental tests with laboratory analogues possible.

Gibbons 和 Hawking ( Phys. Rev. D , 15 (1977) 2738) 已经表明德西特空间的视界发射辐射的方式与黑洞的事件视界相同。但实际的宇宙视界并不是事件视界，德西特空间除外。尽管如此，这篇论文证明了吉本斯和霍金的辐射公式是任何以严格为正的哈勃参数膨胀的平坦空间的精确结果。这篇论文给出了为什么会出现这种情况的直观和直观的见解。该论文还指出了宇宙学视界与动力学卡西米尔效应的关系，这使得实验室类似物的实验测试成为可能。