  In this talk, I discuss the effects, viability, and predictions of the
string-theory-motivated K\"ahler Moduli Inflation I (KMII) potential, coupled
to a light scalar field $\chi$, which can provide a possible source for today's
dark energy density due to the potential's non-vanishing minimum. Although the
model is consistent with the current measured Cosmic Microwave Background (CMB)
data, tighter constraints from future observations are required to test the
viability of the KMII potential with its minimum equivalent to the observed
cosmological constant's energy density $\rho_{\Lambda_{\mathrm{obs}}}$. We
implement a Markov Chain Monte Carlo (MCMC) sampling method to compute the
allowed model parameter ranges and bounds on the inflaton's mass $m_{\phi}$ and
reheating temperature $T_{\mathrm{reh}}$. Additionally, our lattice simulations
predict stochastic gravitational-wave backgrounds generated during the inflaton
oscillations that would be observable today in the $10^{9}$-$10^{11} \,
\mathrm{Hz}$ frequency range. All the results and details will be included in
our upcoming paper with the same title.
