Our Universe Might Be Inside a Black Hole, Explaining Dark Energy

Recent decades have seen the establishment that gravity may be an emergent phenomenon rather than a fundamental force. While frameworks like Jacobson's derivation of Einstein's equations from thermodynamic principles, Verlinde's entropic gravity, and Padmanabhan's extensive thermodynamic interpretations have made strides, they have lacked a concrete physical mechanism for the cosmological constant Λ. This constant is considered the deepest unsolved problem in physics, marked by a 10¹²⁰ discrepancy between observation and quantum field theory.

This new research offers a physical interpretation of Λ by combining emergent gravity with black hole cosmology. As lead author Kang notes in the paper, "The central hypothesis is that the universe exists within a black hole in a parent universe, where steady matter infall from the exterior manifests as constant energy density ρΛ in the interior, providing a concrete, order-of-magnitude physical pathway." This mechanism effectively provides a physical explanation for the cosmological constant.

This framework is mathematically equivalent to the standard ΛCDM cosmological model, successfully reproducing key parameters such as H0=67.43 km/s/Mpc, q0=−0.549, and ztrans=0.67. Rather than solving cosmological paradoxes, this interpretation naturalizes them through open-system energetics and inevitable transition dynamics. The paper suggests potentially testable implications for future observations, all while remaining equivalent to ΛCDM at the background level.