2018/03/31 by Latham Boyle, Kieran Finn, Neil Turok · 1 voice · 4 citations
Physics and Astronomy · #Astrophysics #Cold dark matter #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Massless particle #Neutrino #Particle physics #Particle physics theoretical and experimental studies #Physics #Theoretical physics #Universe #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevlett.121.251301
published as Phys. Rev. Lett. 121, 251301 (2018) · 5 pages, matches version published in PRL
openalex created_date 2018/04/06 · arxiv created 2018/12/02 · openalex publication_date 2018/12/20 · arxiv updated 2018/12/26 · openalex updated_date 2026/08/05
We propose that the state of the universe does \it not spontaneously violate CPT. Instead, the universe after the big bang is the CPT image of the universe before it, both classically and quantum mechanically. The pre- and post-bang epochs comprise a universe/anti-universe pair, emerging from nothing directly into a hot, radiation-dominated era. CPT 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~\rm GeV. Several other testable predictions follow: (i) the three light neutrinos are Majorana 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 CP problem and the arrow of time.