Author Description

In quantum field theory in curved spacetime, one can use covariant quantities constructed from renormalized stress-energy tensor (RSET), for example the energy density, flux and pressure, to describe the quantum radiation from the curved background. In a general gravitational collapse geometry, we use the global null coordinates and define the scaling factor which describes the amount of redshift when null rays pass through the collapsing matter. By computing the RSET of the (1+1) dimensional massless scalar field in the s-wave approximation, we express the covariant quantities as a function of the scaling factor. These quantities separate into two contributions: one determined by the ingoing field modes is dependent on the Schwarzschild metric exterior to the classical matter, the other determined by the outgoing field modes is dependent on the details of how the matter collapsed. The former also depends on the trajectory of the observer and the latter is in the form of Schwarzian derivative of the scaling factor. For all timelike observers, the difference between the pressure and energy density is determined by the trace anomaly and has a universal form that is a property of the Schwarzschild metric. The difference between the energy density and flux is also independent of how the collapse happened, but is dependent on the Schwarzschild metric as well as the trajectory of the observer. We also compute other quantities that account for the observer's acceleration in this general collapse scenario. We find the effective temperature separates into a collapse-dependent Hawking contribution and a trajectory-dependent Unruh contribution. However, these contributions interfere in the covariant quantities constructed from perception renormalized stress-energy tensor (PeRSET).