Is loop quantization in cosmology unique?

被引:110
作者
Corichi, Alejandro [1 ,2 ]
Singh, Parampreet [3 ]
机构
[1] Univ Nacl Autonoma Mexico, Inst Matemat, Unidad Morelia, Morelia 58090, Michoacan, Mexico
[2] Penn State Univ, Ctr Fundamental Theory, Inst Gravitat & Cosmos, University Pk, PA 16802 USA
[3] Perimeter Inst Theoret Phys, Waterloo, ON N2L 2Y5, Canada
关键词
D O I
10.1103/PhysRevD.78.024034
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We reexamine the process of loop quantization for flat isotropic models in cosmology. In particular, we contrast different inequivalent "loop quantizations" of these simple models through their respective successes and limitations and assess whether they can lead to any viable physical description. We propose three simple requirements which any such admissible quantum model should satisfy: (i) independence from any auxiliary structure, such as a fiducial interval/cell introduced to define the phase space when integrating over noncompact manifolds; (ii) existence of a well defined classical limit, and (iii) a sensible "Planck scale" where quantum gravitational effects become manifest. We show that even when it may seem that one can have several possible loop quantizations, these physical requirements considerably narrow down the consistent choices. Apart from the so-called improved dynamics of loop quantum cosmology, none of the other available inequivalent loop quantizations pass the above tests, showing the limitations of lattice refinement models to approximate the homogeneous sector and loop modified quantum geometrodynamics. We conclude that amongst a large class of loop quantizations in isotropic cosmology, there is a unique consistent choice.
引用
收藏
页数:13
相关论文
共 50 条
[1]  
[Anonymous], ARXIV07091621
[2]   Quantum nature of the big bang [J].
Ashtekar, A ;
Pawlowski, T ;
Singh, P .
PHYSICAL REVIEW LETTERS, 2006, 96 (14)
[3]   Background independent quantum giravity: a status report [J].
Ashtekar, A ;
Lewandowski, J .
CLASSICAL AND QUANTUM GRAVITY, 2004, 21 (15) :R53-R152
[4]   Quantum gravity, shadow states and quantum mechanics [J].
Ashtekar, A ;
Fairhurst, S ;
Willis, JL .
CLASSICAL AND QUANTUM GRAVITY, 2003, 20 (06) :1031-1061
[5]  
ASHTEKAR A, COMMUNICATION
[6]  
Ashtekar A., ARXIVGRQC0612104
[7]  
Ashtekar A., UNPUB
[8]   Loop quantum cosmology of k=1 FRW models [J].
Ashtekar, Abhay ;
Pawlowski, Tomasz ;
Singh, Parampreet ;
Vandersloot, Kevin .
PHYSICAL REVIEW D, 2007, 75 (02)
[9]   Quantum nature of the big bang: Improved dynamics [J].
Ashtekar, Abhay ;
Pawlowski, Tomasz ;
Singh, Parampreet .
PHYSICAL REVIEW D, 2006, 74 (08)
[10]   Quantum nature of the big bang: An analytical and numerical investigation [J].
Ashtekar, Abhay ;
Pawlowski, Tomasz ;
Singh, Parampreet .
PHYSICAL REVIEW D, 2006, 73 (12)