2013/05/31 by Tao Zhu, Wen Zhao, Yongqing Huang +2 · 3 citations
Earth and Planetary Sciences · Mathematics · Physics and Astronomy · #Bispectrum #Black Holes and Theoretical Physics #Cosmic microwave background #Cosmology and Gravitation Theories #General relativity #Geophysics and Gravity Measurements #Gravitation #Gravitational wave #Mathematical physics #Mathematics #Non-Gaussianity #Operator (biology) #Order (exchange) #Parity (physics) #Physics #Quantum mechanics #Spectral density #Theoretical physics #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.88.063508
published as Phys. Rev. D88, 063508 (2013) · Revtex4, six figures
openalex publication_date 2013/09/04 · arxiv created 2013/10/26 · arxiv updated 2013/10/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In this paper, we study the effects of parity violation on non-Gaussianities of primordial gravitational waves in the framework of the Ho\ifmmode \checkr\else \vr\fiava-Lifshitz theory of gravity, in which high-order spatial derivative operators, including the ones violating parity, generically appear. By calculating the three-point function, we find that the leading-order contributions to the non-Gaussianities come from the usual second-order derivative terms, which produce the same bispectrum as that found in general relativity. The contributions from high-order spatial nth derivative terms are always suppressed by a factor (H/M*)^n\ensuremath-2(n\ensuremath≥3), where H denotes the inflationary energy and M* the suppression mass scale of the high-order spatial derivative operators of the theory. Therefore, the next leading-order contributions come from the three-dimensional gravitational Chern-Simons term. With some reasonable arguments, it is shown that this three-dimensional operator is the only one that violates the parity and in the meantime has nonvanishing contributions to non-Gaussianities.