Are latest detected events of gravitational waves in favor of some
  models of inflation based on string theory?
  The general potential of power-law inflation is as $ V(\phi)\propto \phi^{n}
$ with scalar field $\phi$. The behavior of inflation is often known as
power-law expansion like $S(\eta)\propto \eta^{1+\beta}$ with $1+\beta<0$. In
this paper, the theoretical spectra of relic gravitational waves are compared
with the measured strain sensitivity of Advanced LIGO and VIRGO, corresponding
to the latest detected events of gravitational waves. The results show tight
constraints on $\beta$ and $n$. Also, the obtained constraints indicate that
special types of the potential of inflation, prototype, and KKLTI models, which
are originated from string theory, are more suitable than other models. Our
analysis shows that there exist some more chances for the detection of relic
gravitational waves.
