Deriving loop quantum cosmology dynamics from diffeomorphism invariance
Deriving loop quantum cosmology dynamics from diffeomorphism invariance
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DOI:
10.1103/physrevd.98.023505
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发表时间:
2018-02
影响因子:
5
通讯作者:
J. Engle;Ilya Vilensky
中科院分区:
文献类型:
--
作者:
J. Engle;Ilya Vilensky
We use the requirement of diffeomorphism invariance in the Bianchi I context to derive the form of the quantum Hamiltonian constraint. After imposing the correct classical behavior and making a certain minimality assumption we then obtain a unique expression for the quantum Hamiltonian operator for Bianchi I to leading order in $\hbar$. Specifically, this expression is found to exactly match the form proposed by Ashtekar and Wilson-Ewing in the loop quantum cosmology (LQC) literature. Furthermore, by using the projection map from the quantum states of the Bianchi I model to the states of the isotropic model, we constrain the dynamics also in the homogeneous isotropic case, and obtain, again to leading order in $\hbar$, a unique quantum constraint which exactly match the standard `improved dynamics' of Ashtekar, Pawlowski and Singh. Our results strengthen confidence in LQC dynamics and its observational predictions as consequences of more basic fundamental principles.