Non-perturbative Lorentzian Quantum Gravity, Causality and Topology Change
Non-perturbative Lorentzian Quantum Gravity, Causality and Topology Change
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DOI：
10.1016/s0550-3213(98)00692-0
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发表时间：
1998-05
期刊：
影响因子：
--
通讯作者：
J. Ambjorn;R. Loll
中科院分区：
文献类型：
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作者：
J. Ambjorn;R. Loll
通过对具有因果结构的几何进行路径积分，我们建立了二维洛伦兹量子引力的非微扰格点模型。该模型可以在离散化水平上精确求解。它的连续极限与在真时规范下量子化二维连续引力所得到的理论相一致，但与用矩阵模型或刘维尔理论定义的二维引力不一致。通过允许紧凑的空间切片的拓扑变化（即婴儿宇宙的创建），一个获得与矩阵模型和刘维尔理论的协议。
We formulate a non-perturbative lattice model of two-dimensional Lorentzian quantum gravity by performing the path integral over geometries with a causal structure. The model can be solved exactly at the discretized level. Its continuum limit coincides with the theory obtained by quantizing 2d continuum gravity in proper-time gauge, but it disagrees with 2d gravity defined via matrix models or Liouville theory. By allowing topology change of the compact spatial slices (i.e. baby universe creation), one obtains agreement with the matrix models and Liouville theory.