The Hourglass Black-white Hole Phase Cycle Cosmological Model

I propose the Hourglass Black-White Hole Phase Cycle Cosmological Model. A star in a parent universe collapses into a black hole that at first holds no universe. When the collapse reaches a maximum curvature, the singularity acts as a reset: energy passes through, but the arrangement of matter, and with it the entropy, does not. A new universe then expands on the other side as a white-hole interior. Two rules connect the levels. The phase rule says that expanding universes form black holes but not white holes, while collapsing universes permit white holes. The timing rule says that a universe can return its contents to its parent only while the parent is collapsing. Dark energy decides the ending: if it stays strong, the contents escape into the parent; if it weakens, the universe recollapses and the cycle repeats. I relate the model to earlier work, list its open problems, and name tests, among them spatial curvature, the evolution of dark energy, and the one observation that would break it: a white hole seen while the universe is clearly expanding.