General Relativity & Quantum Cosmology

The mass of a black hole has traditionally been identified with its energy. We describe a new perspective on black hole thermodynamics, one that identifies the mass of a black hole with chemical enthalpy, and the cosmological constant as thermodynamic pressure. This leads to an understanding of black holes from the viewpoint of chemistry, in terms of concepts such as Van derWaals fluids, reentrant phase transitions, and triple points. Both charged and rotating
black holes exhibit novel chemical-type phase behaviour, hitherto unseen.

Gravitational waves (GW) imprint apparent Doppler shifts on the frequency of photons propagating between an emitter and detector of light. This forms the basis of a method to detect mHz GW using Doppler velocimetry between pairs of satellites [1]. The crucial component in such GW detectors is the frequency standard on board the emitting and receiving satellites. I will discuss how recent developments in atomic clock technology have led to devices that could be sufficiently sensitive to probe astrophysically interesting sources. I will present a design for a robust, space-capable optical frequency standard [2], that is being developed at York.

References

[1] JW Armstrong, Living Rev. Relativity 9, (2006), 1 [2] AC Vutha, arXiv:1501.01733 (2015)