# Hawking radiation Hawking radiation refers to the process by which black holes emit particles and energy due to quantum mechanical effects near the event horizon. By studying QFT on a curved background, it can be shown that a particle and an antiparticle can be created near the event horizon of a black hole, following which there is a chance that one particle falls into the black hole while the other escapes. The escaping particle becomes real and takes away energy from the black hole, causing it to lose mass over time. This process is known as Hawking radiation. Because black holes are predicted to emit particles and energy through this process, they are expected to slowly evaporate over time. In asymptotically flat spacetime, the rate of evaporation is inversely proportional to the mass of the black hole, so smaller black holes evaporate more quickly than larger ones. Even though there is not a complete theory of quantum gravity, QFT on curved spacetimes are believed to be good approximations at the semiclassical level. The discovery of Hawking radiation is therefore an important step into the realm of quantum gravity, as it gives a concrete prediction for what happens when quantum mechanics and gravity greet each other. ## Refs - original - [[1974#Hawking]] - [[1975#Hawking]] ## Examples - JT gravity - [[2024#Dar, Ganai, Kajuri]] - numerical calculations - [[CheslerTeaney2011]][](https://arxiv.org/abs/1112.6196) ## Extensions - with multiple horizons: [[SinghaNandaTripathy2022]][](https://arxiv.org/pdf/2206.06433.pdf) - higher derivative: [[HoKawai2022]][](https://arxiv.org/pdf/2207.07122.pdf) ## Related topics - [[0131 Information paradox]]