A phenomenological description of space-time noise in quantum gravity
A phenomenological description of space-time noise in quantum gravity
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DOI：
10.1038/35074035
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发表时间：
2001-04
期刊：
影响因子：
64.8
通讯作者：
G. Amelino-Camelia
中科院分区：
文献类型：
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作者：
G. Amelino-Camelia
时空“泡沫”是宇宙中最小尺寸尺度的几何图景，其主要特征是距离测量中存在量子不确定性。所有量子引力理论都应该预测某种泡沫，但对这种泡沫性质的描述根据理论而有所不同，从而提供了区分这些理论的可能方法。我之前表明，泡沫引起的距离波动会给重力波干涉仪的测量带来新的噪声源，但理论尚未充分发展，无法进行对实验学家有用的详细预测。在这里，我提出了一种直接描述时空泡沫的唯象方法，这自然会产生与干涉仪细节无关的距离波动图像。模型中唯一未知的是设定效应总体强度的长度尺度，但最近的数据已经排除了该长度尺度可以用“弦长度”（10-34m <Ls< 10-33m）来识别的可能性。甚至比“普朗克长度”（LP≈10-35m）更小的长度尺度也将很快通过实验进行探测。
Space-time ‘foam’ is a geometric picture of the smallest size scales in the Universe, which is characterized mainly by the presence of quantum uncertainties in the measurement of distances. All quantum-gravity theories should predict some kind of foam,, but the description of the properties of this foam varies according to the theory, thereby providing a possible means of distinguishing between such theories. I previously showed that foam-induced distance fluctuations would introduce a new source of noise to the measurements of gravity-wave interferometers, but the theories are insufficiently developed to permit detailed predictions that would be of use to experimentalists. Here I propose a phenomenological approach that directly describes space-time foam, and which leads naturally to a picture of distance fluctuations that is independent of the details of the interferometer. The only unknown in the model is the length scale that sets the overall magnitude of the effect, but recent data already rule out the possibility that this length scale could be identified with the ‘string length’ (10-34m <Ls< 10-33m). Length scales even smaller than the ‘Planck length’ (LP≈ 10-35m) will soon be probed experimentally.