Resolving the Black Hole Information Paradox: A Review of Quantum Extremal Surfaces, Entanglement Islands, and the Page Curve

Anmay Raj

Abstract: A significant theoretical conflict arises between quantum mechanics and general relativity in the form of the black hole information paradox. Traditionally, Hawking radiation suggested that when matter enters a black hole, its information disappears, seemingly violating the unitarity principle central to quantum mechanics. However, recent developments?such as the island formula, quantum extremal surfaces, and holography (particularly AdS/CFT) ?have transformed our understanding of black hole evaporation. This review explores these breakthroughs, focusing on how the Page curve is recovered, indicating that black hole evaporation is, in fact, unitary. We summarize the theoretical progress, highlight key models, and discuss implications for the nature of spacetime and quantum gravity.

Keywords: Black hole information paradox, Hawking radiation, quantum extremal surfaces, entanglement islands, Page curve, holography, AdS/CFT, unitarity, quantum gravity