Review Reports

Round 1

Reviewer 1 Report

The authors study a scalar-torsion theory of gravity, i.e. a theory where a scalar field Φ couples to the torsion invariant T. The torsion invariant T is the Lagrangian for the teleparallel equivalent of general relativity (TEGR). By resorting to methods of dynamical systems, the authors analyze the behavior of the early universe for different choices of the coupling F(Φ) and the potential V(Φ). They employ a Poincare compactification of the dynamical variables to show the heteroclinic orbits beginning at the asymptotic saddle points and going to the final attractor. In each case, the authors consider the consistency of the evolution with the requirements for inflation.

The article is very well written and illustrated. It is a valuable contribution that deserves to be published in Universe. 

Author Response

We thank the referee for reading and evaluating our manuscript.

Reviewer 2 Report

I attached my report as  a pdf file. 

Comments for author File: Comments.pdf

Author Response

We thank the referee for a careful reading and commenting of the manuscript. Responding point by point:
1. Yes, the typos will be corrected.
2. Indeed the action formulae were adopted from the other metric signature convention, and we have corrected the signs in Eq. (1) and (3). The cosmological equations (5)-(7) and (8)-(10), however, are correct, and we supplied extra references there. Supposedly the suggestion to change the sign of the potential and its gradient in the cosmological equations was made with tongue in cheek by the referee, as the system would become unstable this way.

Round 2

Reviewer 2 Report

 I recommend this paper for publication in the journal Universe.