2014/10/31 by S. M. M. Rasouli, Paulo Vargas Moniz · 1 citation
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Classical mechanics #Cosmology and Gravitation Theories #Geometry #Inflation (cosmology) #Mathematical physics #Mathematics #Minisuperspace #Noncommutative and Quantum Gravity Theories #Noncommutative geometry #Noncommutative quantum field theory #Physics #Quantum cosmology #Quantum gravity #Quantum mechanics #Scalar (mathematics) #Scalar field #Theoretical physics #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.90.083533
published as Phys. Rev. D 90, 083533 (2014) · 15 pages, 10 figures
openalex publication_date 2014/10/31 · arxiv created 2014/11/05 · arxiv updated 2014/11/06 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In this paper, we introduce a noncommutative version of the Brans-Dicke (BD) theory and obtain the Hamiltonian equations of motion for a spatially flat Friedmann-Lema\\itre-Robertson-Walker universe filled with a perfect fluid. We focus on the case where the scalar potential as well as the ordinary matter sector are absent. Then, we investigate gravity-driven acceleration and kinetic inflation in this noncommutative BD cosmology. In contrast to the commutative case, in which the scale factor and BD scalar field are in a power-law form, in the noncommutative case the power-law scalar factor is multiplied by a dynamical exponential warp factor. This warp factor depends on the noncommutative parameter as well as the momentum conjugate associated to the BD scalar field. We show that the BD scalar field and the scale factor effectively depend on the noncommutative parameter. For very small values of this parameter, we obtain an appropriate inflationary solution, which can overcome problems within BD standard cosmology in a more efficient manner. Furthermore, a graceful exit from an early acceleration epoch towards a decelerating radiation epoch is provided. For late times, due to the presence of the noncommutative parameter, we obtain a zero acceleration epoch, which can be interpreted as the coarse-grained explanation.