152 research outputs found

    CP violation and gravity as the weakest force

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    We argue that CP violation has rather dramatic impact on the "gravity as the weakest force" conjecture. Namely we find that new ultraviolet scale must be Λ≲θg3MP\Lambda \lesssim \theta g^3 M_P, where θ\theta is an effective parameter describing CP violation and gg is the gauge coupling constant. The bound implies that CP-conserving limit is discontinuous, and possibly indicates that the class of effective theories with strict CP conservation is inconsistent with a fundamental theory incorporating quantum gravity. At the same time, the mass hierarchy problem can be explained due to the smallness of the CP violation, θ∼10−15\theta \sim 10^{-15} or so.Comment: 4 page

    Diffeomorphism-invariant noncommutative gravity with twisted local Lorentz invariance

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    We propose a new theory of gravitation on noncommutative space-time which is invariant under the general coordinate transformations, while the local Lorentz invariance is realized as twisted gauge symmetry. Our theory is remarkably simpler compared to the existing formulations of noncommutative gravity.Comment: 7 pages; v2 to be published in EJT
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