A Built-in Inflation in the $f(T)$-Cosmology

Understand

In the present work we derive an exact solution of an isotropic and homogeneous Universe governed by $f(T)$ gravity.

• We show how the torsion contribution to the FRW cosmology can provide a \textit{unique} origin for both early and late acceleration phases of the Universe.
• The three models ($k=0, \pm 1$) show a \textit{built-in} inflationary behavior at some early Universe time; they restore suitable conditions for the hot big bang nucleosynthesis to begin.
• Unlike the standard cosmology, we show that even if the Universe initially started with positive or negative sectional curvatures, the curvature density parameter enforces evolution to a flat Universe.