  The nature of dark energy is one of the fundamental problems in cosmology.
Introduced to explain the apparent acceleration of the Universe's expansion,
its origin remains to be determined. In this paper, we illustrate a result that
may significantly impact understanding the relationship between dark energy and
structure formation in the late-epoch Universe. Our analysis exploits a
scale-dependent energy functional, initially developed for image visualization,
to compare the physical and geometrical data that distinct cosmological
observers register on their celestial spheres. In the presence of late-epoch
gravitational structures, this functional provides a non-perturbative technique
that allows the standard Friedmann-Lema\^itre-Robertson-Walker (FLRW) observer
to evaluate a measurable, scale-dependent difference between the idealized FLRW
past light cone and the physical light cone. From the point of view of the FLRW
observer, this difference manifests itself as a redshift-dependent correction
$\Lambda^{(corr)}(z)$ to the FLRW cosmological constant $\Lambda^{(FLRW)}$. At
the scale where cosmological expansion couples with the local virialized
dynamics of gravitational structures, we get $\Lambda^{(corr)}(z)\sim
10^{-52}\,m^{-2}$, indicating that the late-epoch structures induce an
effective cosmological constant that is of the same order of magnitude as the
assumed value of the FLRW cosmological constant, a result that may lead to an
interpretative shift in the very role of dark energy.
