On Number of Nflation Fields

Understand

We study the Nflation model, in which a collection of massive scalar fields drive the inflation simultaneously.

• We find, when the number of fields is larger than the square of ratio of the Planck scale $M_p$ to the average value $\bar m$ of fields masses, the slow roll inflation region will disappear.
• This suggests that in order to make Nflation responsible for our observable universe, the number of fields driving the Nflation must be bounded by the above ratio.
• This result is also consistent with recent arguments from black hole physics.