C P T -Symmetric Universe
Abstract
We propose that the state of the Universe does not spontaneously violate C P T . Instead, the Universe after the big bang is the C P T image of the Universe before it, both classically and quantum mechanically. The pre- and postbang epochs comprise a universe-antiuniverse pair, emerging from nothing directly into a hot, radiation-dominated era. C P T symmetry selects a unique QFT vacuum state on such a spacetime, providing a new interpretation of the cosmological baryon asymmetry, as well as a remarkably economical explanation for the cosmological dark matter. Requiring only the standard three-generation model of particle physics (with right-handed neutrinos), a Z2 symmetry suffices to render one of the right-handed neutrinos stable. We calculate its abundance from first principles: matching the observed dark matter density requires its mass to be 4.8 ×108 GeV . Several other testable predictions follow: (i) the three light neutrinos are Majorana particles and allow neutrinoless double β decay; (ii) the lightest neutrino is massless; and (iii) there are no primordial long-wavelength gravitational waves. We mention connections to the strong C P problem and the arrow of time.
- Publication:
-
Physical Review Letters
- Pub Date:
- December 2018
- DOI:
- 10.1103/PhysRevLett.121.251301
- arXiv:
- arXiv:1803.08928
- Bibcode:
- 2018PhRvL.121y1301B
- Keywords:
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- High Energy Physics - Phenomenology;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- General Relativity and Quantum Cosmology;
- High Energy Physics - Theory
- E-Print:
- 5 pages, matches version published in PRL