Cosmological Timeline in the Standard Model

Inflationary Epoch

Time: ~10^-36 to 10^-32 seconds after t=0

Role: The primordial vacuum energy drives exponential expansion, solving the horizon and flatness problems and planting the seeds for all future structure through quantum fluctuations.

The Hot Big Bang Phase Begins

Time: After ~10^-32 seconds

Role: The inflaton field decays in a process called reheating, converting its energy into the hot, dense plasma of particles and radiation that characterizes the traditional Big Bang picture.

ΛCDM Model Evolution

Time: From the end of inflation to the present day (~13.8 Billion years)

Role: Describes the universe's evolution governed by its key constituents:

Λ (Dark Energy): Dominates the universe's current energy budget, causing the accelerated expansion.

CDM (Cold Dark Matter): Provides the gravitational scaffolding for the formation of galaxies and clusters.

Baryonic Matter: The ordinary atoms that make up stars, planets, and life.