  Both long and short gamma-ray bursts (GRBs) are expected to occur in the
dense environments of active galactic nuclei (AGN) accretion disks. As these
bursts propagate through the disks they live in, they photoionize the medium
causing time-dependent opacity that results in transients with unique spectral
evolution. In this paper we use a line-of-sight radiation transfer code
coupling metal and dust evolution to simulate the time-dependent absorption
that occurs in the case of both long and short GRBs. Through these simulations,
we investigate the parameter space in which dense environments leave a
potentially observable imprint on the bursts. Our numerical investigation
reveals that time dependent spectral evolution is expected for central
supermassive black hole masses between $10^5$ and $5 \times 10^7$ solar masses
in the case of long GRBs, and between $10^4$ and $10^7$ solar masses in the
case of short GRBs. Our findings can lead to the identification of bursts
exploding in AGN disk environments through their unique spectral evolution
coupled with a central location. In addition, the study of the time-dependent
evolution would allow for studying the disk structure, once the identification
with an AGN has been established. Finally, our findings lead to insight into
whether GRBs contribute to the AGN emission, and which kind, thus helping to
answer the question of whether GRBs can be the cause of some of the as-of-yet
unexplained AGN time variability.
