Dark Energy & Gravitational Condensate Stars, Or What’s the (Quantum) Matter with Black Holes?
The difficulties in reconciling Einstein’s classical General Relativity and quantum theory reach their apex in the twin puzzles of black holes and cosmological dark energy. Both of these problems are evidence that the gravitational sector of the Standard Model is incomplete at macroscopic distance scales. Indeed when General Relativity is treated as a low energy Effective Field Theory, it can be shown that it necessarily receives infrared relevant corrections from the fluctuations of massless or light quantum fields. The associated conformal anomaly implies the existence of a new massless scalar degree of freedom in gravity, which has long range gravitational effects, that in particular are significant in the vicinity of black hole event horizons. This scalar conformalon also allows the effective value of the vacuum energy, described as a condensate of an exact 4-form abelian gauge field strength F = dA, to change in space and time. The resulting EFT thus replaces the fixed constant Λ of classical gravity, and its unnaturally large sensitivity to UV physics, with a dynamical condensate whose ground state value vanishes identically in empty flat space. By also allowing Λeff to vary rapidly near the 2-surface of a black hole horizon, the proposed EFT of dynamical vacuum energy provides an effective Lagrangian framework for gravitational vacuum condensate stars, as the final non-singular state of complete gravitational collapse, consistent with quantum theory. A gravitational condensate star replaces the classical black hole event horizon by a surface and its interior by a vacuum condensate with dark energy eq. of state, p = – rho, with no entropy and no information paradox. The prospects for testing this EFT in gravitational wave and cosmological observations will be discussed.