PIRSA:11110119

Curvature and Anisotropy Near a Nonsingular Bounce

Xue, B. (2011). Curvature and Anisotropy Near a Nonsingular Bounce. Perimeter Institute. https://pirsa.org/11110119

Xue, BingKan. Curvature and Anisotropy Near a Nonsingular Bounce. Perimeter Institute, Nov. 10, 2011, https://pirsa.org/11110119 

          @misc{ pirsa_PIRSA:11110119,
            doi = {10.48660/11110119},
            url = {https://pirsa.org/11110119},
            author = {Xue, BingKan},
            keywords = {Cosmology},
            language = {en},
            title = {Curvature and Anisotropy Near a Nonsingular Bounce},
            publisher = {Perimeter Institute},
            year = {2011},
            month = {nov},
            note = {PIRSA:11110119 see, \url{https://pirsa.org}}
          }

BingKan Xue

Princeton University

Talk number
PIRSA:11110119
Collection
Talk Type
Subject
Abstract
Problematic growths of curvature and anisotropy are found in nonsingular bouncing cosmologies that include both an ekpyrotic phase and a bouncing phase. Classically, initial curvature and anisotropy that are suppressed during the ekpyrotic phase will grow back exponentially during the nonsingular bouncing phase. Besides, curvature and shear perturbations are generated by quantum fluctuations during the ekpyrotic phase. In the bouncing phase, an adiabatic curvature perturbation grows to dominate and gives rise to a blue spectrum that spoils the scale-invariance. Meanwhile, a scalar shear perturbation grows nonlinear and creates an overwhelming anisotropy that disrupts the nonsingular bounce altogether. We examine the common origin of these problems and discuss possible ways to avoid them.