cette

feminine singular of ce

théorie

1. theory
2. solemn or sacred procession or embassy, especially in ancient Greece
3. procession; group of people moving in single file; a row, line

s'est

se + est (third-person singular indicative present form of être)

avérée

feminine singular of avéré

particulièrement

1. particularly, specifically
2. especially
3. in particular

féconde

feminine singular of fécond