Quantum Instability of the Cauchy Horizon in Reissner-Nordstr\"om-deSitter Spacetime

Understand

In classical General Relativity, the values of fields on spacetime are uniquely determined by their values at an initial time within the domain of dependence of this initial data surface.

• However, it may occur that the spacetime under consideration extends beyond this domain of dependence, and fields, therefore, are not entirely determined by their initial data.
• This occurs, for example, in the well-known (maximally) extended Reissner-Nordstr\"om or Reissner-Nordstr\"om-deSitter (RNdS) spacetimes.
• The boundary of the region determined by the initial data is called the "Cauchy horizon." It is located inside the black hole in these spacetimes.