Includes Reference

The advent of modern satellite technology has transformed observational astronomy and
astrophysics, offering unprecedented insights into the large-scale behavior of gravitation and
challenging established cosmological models. This technological progress has reinvigorated
the study of relativistic cosmology, leading to a critical reassessment of foundational
assumptions, particularly the cosmological principle, which posits that the universe is
homogeneous and isotropic on large scales. While this principle underpins the Standard
Cosmological Model (SCM) and the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric,
emerging data has increasingly been challenging its validity. Central to this investigation are
the redshift-distance and light intensity-distance relations, essential for testing cosmological
models. The integration of both parametric and nonparametric redshift models provides a
more comprehensive analysis, addressing discrepancies in our understanding of the universe's
structure and evolution. However, unresolved mysteries, particularly concerning dark matter
and dark energy, complicate these models. This research critically examines the cosmological
principle using the latest observational data and scrutinizes the Friedmann model's
assumptions. The study reveals that galaxy formation occurred most rapidly in the early
universe, particularly within the redshift range of 0 < 𝑧 < 0.4, peaking around 𝑧 ≈ 0.8. It also
highlights that dark matter plays a significantly more critical role than dark energy in this
process. While dark energy primarily affects the large-scale expansion of the universe, dark
matter seems to dominate local galaxy formation and the evolution of cosmic structures. These
findings underscore the limitations of current models and contribute to the ongoing refinement
of cosmological theories, offering a clearer understanding of the universe’s evolution.