We propose a conceptual dual-holographic cosmological model in which the observable universe emerges as a thermodynamic projection across a scalar field, defined on a dynamically stabilized event horizon (EH) that separates an AdS-like quantum interior from a dS-like geometric exterior. This EH field mediates the transition between gravitational and quantum domains and forms a bidirectional holographic interface that connects an AdS/CFT correspondence in the interior (Maldacena et al. {1997}; Witten et al. {1998}) with a conjectured dS/CFT structure on the cosmological side (Strominger et al. {2001}).The model is based on the concept of Grey Holes (GHs)—non-singular gravitational configurations stabilized by thermodynamic consistency and negative heat capacity—where the EH acts as a critical interface with vanishing entropy density and heat flux (Bekenstein et al. {1973}, Hawking et al. {1975}). This interface induces entropic gradients that define the arrow of time and generate spacetime geometry. Inward-directed entropy flows within the AdS region reproduce attractive gravity in line with entropic gravity models (Verlinde et al. {2011}, Jacobson et al. {1995}, Admanabhan et al. {2010}), while outward-directed entropy flow in the dS region gives rise to an effective cosmological repulsion without requiring a fundamental dark energy component.Key cosmological observables—such as the Hubble parameter, the CMB temperature, and the effective energy density—emerge from the dynamics of the EH field, yielding predictions consistent with current observations and potentially testable deviations from the CDM model.Although formulated macroscopically, this approach conceptually resonates with entropy-based quantum gravity (EQG) models (Bianconi et al. {2019, 2021, 2023}), which describe emergent spacetime via microscopic network geometries and information-theoretic principles. Both approaches suggest that gravity and temporality may arise from entropic flows across structured boundaries—be they quantum networks or cosmological horizons.By framing cosmology as a dual-holographic, thermodynamically driven interface theory, this model offers a speculative but coherent alternative to inflation and dark energy, grounded in the synergy between geometric dualities and entropic emergence.