Frequency shift of light emitted from growing and shrinking black holes

In this paper we present a method to study the frequency shift of signals sent from near Schwarzschild black hole that grows or shrinks through accretion. We construct numerical solution Einstein's equations sourced by spherical shell scalar field, with positive energy density simulate growth and negative shrink horizon. launch distribution null rays at various time slices during accretion estimate their along own trajectories. Spatially bundles photons are distributed according dust, whose dynamics obeys Euler in test field limit evolution hole. With these elements, process contraction hole, which shows variability depends on thickness equivalently timescale