The exact nature of dark energy remains one of the biggest unsolved problems in physics. Several hypotheses have been proposed:
Cosmological Constant: Introduced by Albert Einstein, this theory suggests that dark energy is a constant energy density filling space homogeneously. Quintessence: This theory proposes that dark energy is a dynamic field that changes over time and space. Modified Gravity Theories: These theories suggest that modifications to our current understanding of gravity could explain the accelerated expansion without invoking dark energy.
