content_image/367769.jpg
thus lower the influence of cosmic strings on the CMB, and 

<img src='content_image/367769.jpg'>

2) predict a spectral index lower than 0 . 98, easily in the range n$_{s}$ ∈ [0 . 9 , 1] as represented in Fig. (4). 

## 6. Initial conditions for F -term hybrid inflation 

We have seen in Sec. IV C that initial conditions for hybrid inflation was considered one of the challenges for the hybrid models, and it was considered as a problem for the F -term inflation in [537]. It was argued that for inflation to be successful, the initial field value for the waterfall field ψ$_{i}$ had to be fine-tuned to an almost vanishing value, so as to start close 

