Primordial Core Hypothesis: Early Galaxy Formation Driven by Primordial Black Holes (PBHs)

This work presents the Primordial Core Hypothesis (PCH), a theoretical framework proposing that a rare population of massive primordial black holes (PBHs), formed during the radiation-dominated era, can act as gravitational seeds for the earliest galaxies. Unlike conventional models that rely on stellar remnants or direct-collapse black holes, PCH explores how pre-existing compact objects can accelerate early structure formation by deepening central gravitational potentials and enhancing baryonic inflow. The framework emphasizes selective formation and survival, focusing on a suppressed heavy tail of the primordial black hole mass function produced within a narrow, mode-selective inflationary window. Only PBHs that remain centrally embedded and dynamically stable over cosmological timescales are expected to contribute to observable early galaxies, introducing a natural central survivorship bias. This hypothesis does not claim that all galaxies host primordial black holes at their centers; rather, it argues that if primordial black holes persist to late times, their highest probability of survival and observational relevance is at galactic centers. The work outlines analytical scaling arguments, consistency with current observational constraints, and testable predictions relevant to high-redshift galaxies, quasars, and future gravitational-wave observations.