Mathematical concepts such as differential geometry are fundamental to the study of general relativity and cosmology. In general relativity, differential geometry is used to describe the curvature of spacetime, which is influenced by the distribution of matter and energy. This curvature is mathematically represented by the metric tensor, which is a key component of Einstein's field equations. Cosmology, on the other hand, utilizes differential geometry to study the large-scale structure and dynamics of the universe, including phenomena such as cosmic expansion, gravitational lensing, and the formation of galaxies and galaxy clusters. By applying advanced mathematical tools from differential geometry, physicists and cosmologists can better understand the intricate relationships between matter, energy, space, and time in the context of general relativity and cosmology.