Exploring Dark Matter and Dark Energy: Current Understanding and Challenges

Review Article

Abstract

Particle Dark matter and dark energy together constitute nearly 95% of the total energy density of the universe, yet their fundamental nature remains one of the most profound and unresolved problems in modern physics and cosmology. This review provides a comprehensive overview of the current understanding of these elusive components, focusing on observational evidence, theoretical frameworks, and ongoing experimental efforts. Dark matter is primarily inferred from its gravitational influence on visible matter, radiation, and the large-scale structure of the universe, with key evidence arising from galactic rotation curves, gravitational lensing, and cosmic microwave background measurements. In contrast, dark energy is introduced to explain the observed accelerated expansion of the universe, as revealed by distant Type Ia supernovae and large-scale cosmological surveys. Despite substantial progress in both observational and theoretical domains, neither dark matter nor dark energy has been directly detected, posing significant challenges to the Standard Model of particle physics and the theory of general relativity. Various theoretical candidates have been proposed for dark matter, including weakly interacting massive particles, axions, and other exotic particles, while dark energy is often associated with the cosmological constant or dynamic scalar fields. The review also examines recent advancements in experimental and observational techniques, including underground detectors, space-based telescopes, and large-scale surveys, which aim to constrain the properties of these components with increasing precision. Furthermore, it highlights the growing interplay between particle physics, astrophysics, and cosmology in addressing these questions.