Video URL
https://pirsa.org/17080016The exponential expansion of the universe from unrenormalised energy momentum tensor
APA
Unruh, B. (2017). The exponential expansion of the universe from unrenormalised energy momentum tensor. Perimeter Institute for Theoretical Physics. https://pirsa.org/17080016
MLA
Unruh, Bill. The exponential expansion of the universe from unrenormalised energy momentum tensor. Perimeter Institute for Theoretical Physics, Aug. 03, 2017, https://pirsa.org/17080016
BibTex
@misc{ scivideos_PIRSA:17080016, doi = {10.48660/17080016}, url = {https://pirsa.org/17080016}, author = {Unruh, Bill}, keywords = {Cosmology}, language = {en}, title = {The exponential expansion of the universe from unrenormalised energy momentum tensor}, publisher = {Perimeter Institute for Theoretical Physics}, year = {2017}, month = {aug}, note = {PIRSA:17080016 see, \url{https://scivideos.org/pirsa/17080016}} }
Bill Unruh University of British Columbia
Abstract
The unrenormalised energy momentum tensor is both huge and fluctuating from point to point. Taking this seriously we (Qingdi Wang, Zhen Zhu, and myself) argue that the slow exponential expansion of the universe (on time scales of 10^10 years) comes from a very weak parametric resonance induced by the fluctuating energy mementum tensor on the rapidly fluctuating scale factor (on time scales much shorter than the Planck scale). We see only the slow exponential growth because we avarage over the scale factor squared.