Atlas of Fundamental Concepts

The black-hole branch follows Einstein’s equation to Schwarzschild and Kerr spacetimes, collapse, horizons, binaries, gravitational-wave detection, and semiclassical Hawking radiation. The cosmology branch imposes large-scale homogeneity and isotropy, yielding FLRW geometry and Friedmann dynamics. Expansion supports the hot Big Bang; the cosmic microwave background tests it; inflation supplies an early accelerated phase; dark matter and dark energy enter the concordance $\Lambda$CDM model.