Joint Gravity/ Particle Theory Seminar

Thu, Apr 25, 2019 2:00 pm - 3:30 pm
PSC 3150


Latham Boyle, Perimeter Institute

Title: CPT-Symmetric Universe

Abstract: I will introduce our recent proposal that the state of the universe does *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 the QFT vacuum state on such a spacetime, providing a new interpretation of the cosmological baryon asymmetry, as well as an economical explanation for the cosmological dark matter. Requiring only the standard three-generation model of particle physics (with right-handed neutrinos), a Z_2 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 x 10^{8} GeV. Several other testable predictions follow: (i) the three light neutrinos are Majorana and allow neutrinoless double beta decay; (ii) the lightest neutrino is massless; and (iii) there are no primordial long-wavelength gravitational waves. The proposal also has interesting things to say about the strong CP problem and the observed electrodynamic arrow of time.

Upcoming Events

20 May
CMTC Spring Symposium
Mon, May 20, 2019 11:00 am - 4:15 pm
21 May
CMTC Spring Symposium
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Physics Colloquium
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PChem/ANE/ChemPhys Seminar
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