GibbonsHawking

GibbonsHawking refers to the collective contributions of Gary Gibbons and Stephen Hawking to the thermodynamics of spacetime horizons, particularly in de Sitter space. Their work showed that horizons arising from the expansion of the universe can behave thermally, extending horizon thermodynamics beyond black holes to cosmological settings.

In their landmark 1977 paper, Gibbons and Hawking demonstrated that observers in de Sitter space perceive a thermal bath with a characteristic temperature, now called the Gibbons-Hawking temperature. This temperature is proportional to the expansion rate of the spacetime, with T = ħH/(2πkB) in appropriate units, where H is the Hubble parameter of the de Sitter geometry. They also established that the cosmological event horizon carries entropy, analogous to black hole horizons, with entropy proportional to the horizon area.

The key results show that a cosmological horizon has thermodynamic properties, including temperature and entropy, suggesting a deep link between gravity, quantum theory, and thermodynamics. These ideas laid groundwork for quantum field theory in curved spacetime and influenced subsequent studies of semiclassical gravity and the thermodynamics of the universe.

Gibbons-Hawking concepts underpin discussions of horizon thermodynamics, the role of cosmological constant and de Sitter space in quantum gravity, and the broader interpretation of horizons as physical systems with thermodynamic descriptions. They are frequently cited in relation to Hawking radiation, black hole thermodynamics, and the ongoing exploration of quantum aspects of spacetime.