Modified Gravity Theories

Modified Gravity Theories propose changes to classical gravitational laws to explain cosmic acceleration and galactic dynamics without invoking dark energy or dark matter. These theories alter the behavior of gravity on large scales or in strong-field regimes. Examples include extensions of general relativity and theories with additional degrees of freedom. Modified gravity theories are motivated by observational discrepancies and theoretical challenges in unifying gravity with quantum physics. They predict deviations from general relativity that can be tested through cosmological observations and astrophysical phenomena. Precision measurements of galaxy clustering, gravitational lensing, and gravitational waves provide constraints. Modified gravity research explores whether gravity itself must be redefined at cosmic scales. This field lies at the intersection of theoretical physics, astrophysics, and cosmology.