2007/03/31 by Xian-Hui Ge, Sang Pyo Kim
Physics and Astronomy · #Age of the universe #Anisotropy #Astrophysics #Big Bang (financial markets) #Big Rip #Black Holes and Theoretical Physics #Brane #Classical mechanics #Cosmic microwave background #Cosmological constant #Cosmology #Cosmology and Gravitation Theories #Dark energy #De Sitter universe #Eccentricity (behavior) #Flatness problem #Galaxies: Formation, Evolution, Phenomena #Metric expansion of space #Particle horizon #Physics #Quantum mechanics #Scale factor (cosmology) #Steady State theory #Theoretical physics #Universe #astro-ph #gr-qc #hep-th
paper · pdf · doi:10.1088/1475-7516/2007/07/001
published as JCAP0707:001,2007 · 15 pages, 1 figure, Version 3, references added, contents expanded
arxiv created 2007/05/18 · openalex publication_date 2007/07/02 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study a scenario of an ellipsoidal universe in the brane world cosmology with a cosmological constant in the bulk. From the five-dimensional Einstein equations we derive the evolution equations for the eccentricity and the scale factor of the universe, which are coupled to each other. It is found that if the anisotropy of our universe originates from a uniform magnetic field inside the brane, the eccentricity decays faster in the bulk in comparison with a four-dimensional ellipsoidal universe. We also investigate an ellipsoidal universe in brane-induced gravity and find the evolution equation for the eccentricity which has a contribution determined by the four- and five-dimensional Newton constants. The role of the eccentricity is discussed in explaining the quadrupole problem of the cosmic microwave background.