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arXiv · 1403.5433

Massive gravitational waves in Chern-Simons modified gravity

Yun Soo Myung·Taeyoon Moon
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Abstract

We consider the nondynamical Chern-Simons (nCS) modified gravity, which is regarded as a parity-odd theory of massive gravity in four dimensions. We first find polarization modes of gravitational waves for $θ=x/μ$ in nCS modified gravity by using the Newman-Penrose formalism where the null complex tetrad is necessary to specify gravitational waves. We show that in the Newman-Penrose formalism, the number of polarization modes is one in addition to an unspecified $Ψ_4$, implying three degrees of freedom for $θ=x/μ$. This compares with two for a canonical embedding of $θ=t/μ$. Also, if one introduces the Ricci tensor formalism to describe a massive graviton arising from the nCS modified gravity, one finds one massive mode after making second-order wave equations, which is compared to five found from the parity-even Einstein-Weyl gravity.

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Yun Soo Myung, Taeyoon Moon. 2014-09-29. Massive gravitational waves in Chern-Simons modified gravity. https://doi.org/10.1088/1475-7516%2F2014%2F10%2F043

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