Turnaround and the Beginning of the End: What Follows the Crest of a Breathing Universe
Abstract
If a bounded sinusoidal dark-energy density passes the growth test of the companion paper, the universe turns over at a_max≈1.68 some 15 Gyr hence — a global, mirror-image event whose one visible signature is the cosmic shift passing through zero (the last unshifted sky) before contraction blueshifts the sky. This paper sequences the collapse and shows it cannot be undone: the steepest contraction term the class owns scales as a⁻⁴ while shear scales as a⁻⁶, so anisotropy (BKL) destroys the homogeneous description at white-dwarf density, ~69 e-folds before any quantum-gravity bounce. No breathing cosmology of this class can be made cyclic.
Fields of Study & Subjects
Cosmology and Gravitation Theories
Relativity and Gravitational Theory
Black Holes and Theoretical Physics
Publication details
- Journal / source
- Zenodo (CERN European Organization for Nuclear Research)
- Publication date
- 21 July 2026
- Document type
- Preprint