Black-hole event horizons have high space curvature and high tidal forces, and so form virtual-particle pairs. Sometimes, one virtual particle enters black hole, and the other escapes and becomes a real particle {Hawking radiation}. It is like quantum tunneling. In-falling and escaping particles carry energy. Negative energy flows into black hole, reducing mass-energy density, and positive energy escapes, reducing mass-energy, so energy conservation energy holds overall, but black-hole mass and energy decrease {black hole evaporation}. Hawking radiation decreases black-hole mass and energy, so event horizon has shorter radius and smaller surface area.
Spatial-surface gravity determines particle-creation amount. Mass-energy-loss rate varies inversely with mass squared, so smaller black holes radiate more rapidly and lose mass faster. Smallest ones can explode. Smallest ones radiate particles with no spin. Small ones radiate neutrons and other neutral particles with spin in equatorial plane. Large ones radiate protons, electrons, and other charged particles. Largest ones radiate photons and gravitons. Equal numbers of baryons and anti-baryons leave black holes.
However, outside space also creates virtual photons, and some enter black holes, so typical black holes probably are in thermal equilibrium with surrounding space and do not evaporate.
temperature
Hot objects radiate to cooler objects. Warm objects radiate infrared light. Light-frequency distribution depends on object temperature. Black holes radiate Hawking radiation, and event-horizon temperature determines frequency distribution. Event-horizon temperature varies inversely with black-hole surface area and mass. Smaller black holes have higher energy-to-mass ratio and so higher temperature. Large black holes have event-horizon temperatures near absolute zero. Tiny-black-hole event-horizon temperatures are 10^21 K.
Black holes have high gravity and attract outside particles. In-falling particles add heat and increase event-horizon temperature.
Hawking radiation reduces black-hole mass more than it reduces energy, so energy-to-mass ratio increases, and so event-horizon temperature rises. Thermal emission reduces black-hole mass and makes black hole hotter.
Black-hole event-horizon temperature results from quark and gluon motions. Black holes have strongly interacting quarks and gluons, which have low shear viscosity. Temperature T varies directly with acceleration a: T = (h / (2 * pi * c)) * a, where c is light speed, and h is Planck constant. T = kappa / (2 * pi), where kappa = (h/c) * a. Particles have high acceleration at event horizon. Larger black holes have smaller particle accelerations, and so lower event-horizon temperatures. Temperature represents quantum-fluctuation strength.
Classically, emitting thermal radiation from hot bodies removes energy and makes surface have lower temperature, because hotter-than-average particles preferentially leave. Does only cooler-than-average radiation leave black holes, so they get hotter? Is virtual radiation thermal emission or another radiation kind?
Physical Sciences>Astronomy>Universe>Cosmology>Singularity>Black Hole
5-Astronomy-Universe-Cosmology-Singularity-Black Hole
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0224