  It is a fact that the universe lives on a Gravitational Wave Background
(GWB), which it may be in the form of extra energy, which is not contained in
Einstein's field equations. In \cite{Matos:2021jef}, a new model was developed
to explain the current accelerating expansion of the universe where a GWB was
incorporated by extending Einstein's equations to
$R_{\mu\nu}-\frac{1}{2}Rg_{\mu\nu}+\frac{2\pi^2}{{\lambda}^2}g_{\mu\nu}=\kappa
^2 T_{\mu\nu}$, where ${\lambda}$ is the Compton wavelength of the graviton. In
the present work we show that this extended form agrees very well with the
observations of Cosmic chronometers, Baryon Acoustic Oscillations and Pantheon
SN type Ia, reproducing the observational data with a $\Delta\chi^2=3.26$ in
favor of the present model compared to the $\Lambda$CDM. The values favored by
these observations are $\Omega_{\rm m} = 0.31 \pm 0.02$, $H_0=68 \pm 0.02$
Km/s/Mpc, $\Omega_{\rm k} = 0.001\pm 0.011$; we also find an excellent
consistence of this model with the Cosmic Microwave Background and the Matter
Power Spectrum. We conclude that this model is an excellent alternative to
explain the accelerating expansion of the universe without incorporating the
cosmological constant.
