Astronomy and Astrophysics – Astrophysics – General Relativity and Quantum Cosmology
Scientific paper
2009-04-28
Phys.Lett.B682:1-7,2009
Astronomy and Astrophysics
Astrophysics
General Relativity and Quantum Cosmology
8 pages, 2 figures
Scientific paper
10.1016/j.physletb.2009.10.072
Since there are quantization ambiguities in constructing the Hamiltonian constraint operator in isotropic loop quantum cosmology, it is crucial to check whether the key features of loop quantum cosmology are robust against the ambiguities. In this paper, we quantize the Lorentz term of the gravitational Hamiltonian constraint in the spatially flat FRW model by two approaches different from that of the Euclidean term. One of the approaches is very similar to the treatment of the Lorentz part of Hamiltonian in loop quantum gravity and hence inherits more features from the full theory. Two symmetric Hamiltonian constraint operators are constructed respectively in the improved scheme. Both of them are shown to have the correct classical limit by the semiclassical analysis. In the loop quantum cosmological model with a massless scalar field, the effective Hamiltonians and Friedmann equations are derived. It turns out that the classical big bang is again replaced by a quantum bounce in both cases. Moreover, there are still great possibilities for the expanding universe to recollapse due to the quantum gravity effect.
Ding You
Ma Yongge
Yang Jinsong
No associations
LandOfFree
Alternative quantization of the Hamiltonian in loop quantum cosmology II: Including the Lorentz term does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Alternative quantization of the Hamiltonian in loop quantum cosmology II: Including the Lorentz term, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Alternative quantization of the Hamiltonian in loop quantum cosmology II: Including the Lorentz term will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-713018