Cosmic evolution with delay differential equations

  • Carl Justin B. Palpal-latoc National Institute of Physics, University of the Philippines Diliman
  • Michael Francis Ian G. Vega, II National Institute of Physics, University of the Philippines Diliman

Abstract

Inflation driven by scalar fields is standard in modern cosmology, though not without shortcomings. Noting nonlocal quantum effects, Choudhury et al. modified the Friedmann equation with a time delay and showed that inflation is possible without such fields. We revisit this delayed cosmology scheme and demonstrate the role of the delay parameters more clearly. We find that in the delayed Friedmann model with an initial power-law history, the universe always prefers an expansion. In fact, inflation is generic and its strength is proportional to the initial energy density. The inflationary period lasts as long as the delay. But interestingly, the universe makes up for a short-lived inflation (due to a short delay) by very slowly decelerating after the rapid expansion, thereby still growing even after inflation.

Published
2020-09-22
How to Cite
[1]
C. J. Palpal-latoc and M. F. I. Vega. Cosmic evolution with delay differential equations, Proceedings of the Samahang Pisika ng Pilipinas 38, SPP-2020-2G-06 (2020). URL: https://paperview.spp-online.org/proceedings/article/view/SPP-2020-2G-06.
Section
Theoretical and Mathematical Physics (Short Presentations)