Entropy Balloon Hypothesis: An Information-Based Alternative to ΛCDM Expansion

This short review presents the Entropy Balloon Hypothesis, a conceptual alternative to the standard ΛCDM cosmological model. Rather than postulating the expansion of physical space, the hypothesis suggests that cosmic acceleration arises from the inflation of locally accessible state-space—an entropy-driven process. Key insights include: A direct analogy between entropy gradients and pressure, An effective equation-of-state parameter w_S derived from entropy growth, Observable predictions for the CMB anisotropy (multipole \ell \approx 20–60), BH mergers, and IR background fluctuations. The document outlines next steps to render the idea testable, offering a novel bridge between thermodynamics, information theory, and cosmology.