Might the radiation era extend back to the Big Bang? On dark matter production and the relic graviton background in quadratic gravity

Latham Boyle, Neil Turok, Vatsalya Vaibhav

Naive estimates based on Einstein gravity with Lagrangian $\frac{1}{2}{M}_{pl}^2(R-2\Lambda )$ suggest that, if the radiation era extended back to the Big Bang (i.e., as far back as the c…