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Non-smooth Gravity and Parity Violation

FOUNDATIONS OF PHYSICS (2019)

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期刊

FOUNDATIONS OF PHYSICS
卷 49, 期 3, 页码 191-201

出版社

SPRINGER
DOI: 10.1007/s10701-019-00240-8

关键词

Nonsmooth gravity; Modified gravity; CP violation

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Physics, Multidisciplinary

资金

  1. National Council for Scientific and Technological Development (CNPq - Brazil)

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A conservative extension of general relativity is proposed by alleviating the differentiability of the metric and allowing for non-smooth solutions. We show that these metrics break some symmetries of the Riemann tensor, yielding a new scalar curvature invariant besides the usual Ricci scalar. To first order in the curvature, this adds a new piece of information to the action, containing interesting and unexplored physics. The spectrum of the theory reveals the presence of an additional massless spin-1 field apart from the massless spin-2 graviton. We argue that this new contribution violates P and CP symmetries at leading order in the curvature and we discuss the possibility of observing these effects in existing experiments.

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