2007/07/17 by Dah-Wei Chiou, Kevin Vandersloot · 1 citation
Physics and Astronomy · #Anisotropy #Big Bang (financial markets) #Big Bounce #Black Holes and Theoretical Physics #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #De Sitter universe #Initial singularity #Isotropy #Loop quantum cosmology #Noncommutative and Quantum Gravity Theories #Physics #Quantum #Quantum cosmology #Quantum gravity #Quantum mechanics #Semiclassical physics #Singularity #Universe #astro-ph #gr-qc
paper · pdf · doi:10.1103/physrevd.76.084015
published as Phys.Rev.D76:084015,2007 · 15 pages, 10 figures
arxiv created 2007/07/17 · openalex publication_date 2007/10/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In homogeneous and isotropic loop quantum cosmology, gravity can behave repulsively at Planckian energy densities leading to the replacement of the big bang singularity with a big bounce. Yet in any bouncing scenario it is important to include nonlinear effects from anisotropies which typically grow during the collapsing phase. We investigate the dynamics of a Bianchi I anisotropic model within the framework of loop quantum cosmology. Using effective semiclassical equations of motion to study the dynamics, we show that the big bounce is still predicted with only differences in detail arising from the inclusion of anisotropies. We show that the anisotropic shear term grows during the collapsing phase, but remains finite through the bounce. Immediately following the bounce, the anisotropies decay and with the inclusion of matter with equation of state w<+1, the universe isotropizes in the expanding phase.