Reflective Resonant Shell Cosmology: Black Hole Duality

Abstract: We propose that the observable universe exists within a finite, closed spatial domain bounded by a dynamic, reflective shell whose surface stress-energy drives cosmic acceleration without requiring a cosmological constant. This Resonant Shell Cosmology (RSC) framework employs Israel junction conditions to relate the shell's tension to the modified Friedmann equation, naturally producing dark energy-like effects through geometric boundary conditions rather than exotic vacuum energy. The model explains cosmic microwave background observations through standing electromagnetic modes in the resonant cavity, predicting distinct observational signatures including suppressed integrated Sachs-Wolfe effects and characteristic spectral distortions.