Turn on the Radio: Challenges to our Understanding of Gamma-ray Burst from their Radio Emission.

Although the standard picture for how we understand gamma-ray bursts (GRBs), the most luminous explosions in our universe, has been remarkably successful at explaining many of their observed properties, it is clear we are missing fundamental pieces of the puzzle.  In the past few years, analyses of their radio emission in particular has brought to light a number of challenges to our standard model. We present recent results showing a dichotomy between long GRBs with and without radio afterglows. These two populations exhibit significantly different observational properties that suggest potentially two distinct progenitor systems.  We explore the possibility that radio bright GRBs originate from massive stars collapsing in interacting binary systems, while radio dark GRBs may come from single (or non-interacting binary) massive stellar deaths.   We also discuss the cosmological evolution of GRB observables in both the radio bright and dark populations, and connect this to their progenitor evolution over cosmic time.