Black hole field theory with a firewall in two spacetime dimensions

We propose that the vacuum state of a scalar field around a black hole is a modified Unruh vacuum. In (1+1) dimensions, we show that a free-faller close to such an horizon can be modeled as an inertial observer in a modified Minkowski vacuum. The modification allows for information-leaking correlations at high frequencies. Using a Gaussian detector centered at k0, we find that the expectation value of the number operator for a detector crossing the horizon is proportional to 1/|k0|, implying that the free-faller will observe unbounded numbers of high-energy photons, i.e. a firewall.