Measuring the Modified Gravitational Wave Propagation beyond General Relativity from CMB Observations
In modified gravity theories, gravitational wave propagations are presented in nonstandard ways. We consider a friction term different from GR and constrain the modified gravitational waves propagation from observations. The modified gravitational waves produce anisotropies and polarization, which g...
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MDPI AG
2022-07-01
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| Series: | Universe |
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| Online Access: | https://www.mdpi.com/2218-1997/8/7/367 |
| _version_ | 1797443282666520576 |
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| author | Jun Li |
| author_facet | Jun Li |
| author_sort | Jun Li |
| collection | DOAJ |
| description | In modified gravity theories, gravitational wave propagations are presented in nonstandard ways. We consider a friction term different from GR and constrain the modified gravitational waves propagation from observations. The modified gravitational waves produce anisotropies and polarization, which generate measurable tensor power spectra. We explore the impact of the friction term on the power spectrum of B-modes and the impact on the constraints on the other parameters (e.g., <i>r</i> or <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>A</mi><mi>t</mi></msub></semantics></math></inline-formula>) when <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ν</mi><mn>0</mn></msub></semantics></math></inline-formula> is allowed to vary in the Monte Carlo analyses from Planck+BK18 datasets. If we assume the result of the scalar perturbations is unchanged, the inflation consistency relation alters with the friction term. In the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula>CDM+<i>r</i>+<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ν</mi><mn>0</mn></msub></semantics></math></inline-formula> model, the tensor-to-scalar ratio and the amplitude of the tensor spectrum are obviously influenced. |
| first_indexed | 2024-03-09T12:53:43Z |
| format | Article |
| id | doaj.art-38f0197b0b4b4b24a38676f8555a509a |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-03-09T12:53:43Z |
| publishDate | 2022-07-01 |
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| record_format | Article |
| series | Universe |
| spelling | doaj.art-38f0197b0b4b4b24a38676f8555a509a2023-11-30T22:02:03ZengMDPI AGUniverse2218-19972022-07-018736710.3390/universe8070367Measuring the Modified Gravitational Wave Propagation beyond General Relativity from CMB ObservationsJun Li0School of Mathematics and Physics, Qingdao University of Science and Technology, Qingdao 266061, ChinaIn modified gravity theories, gravitational wave propagations are presented in nonstandard ways. We consider a friction term different from GR and constrain the modified gravitational waves propagation from observations. The modified gravitational waves produce anisotropies and polarization, which generate measurable tensor power spectra. We explore the impact of the friction term on the power spectrum of B-modes and the impact on the constraints on the other parameters (e.g., <i>r</i> or <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>A</mi><mi>t</mi></msub></semantics></math></inline-formula>) when <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ν</mi><mn>0</mn></msub></semantics></math></inline-formula> is allowed to vary in the Monte Carlo analyses from Planck+BK18 datasets. If we assume the result of the scalar perturbations is unchanged, the inflation consistency relation alters with the friction term. In the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula>CDM+<i>r</i>+<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>ν</mi><mn>0</mn></msub></semantics></math></inline-formula> model, the tensor-to-scalar ratio and the amplitude of the tensor spectrum are obviously influenced.https://www.mdpi.com/2218-1997/8/7/367primordial gravitational wavesmodified friction termCMB observations |
| spellingShingle | Jun Li Measuring the Modified Gravitational Wave Propagation beyond General Relativity from CMB Observations Universe primordial gravitational waves modified friction term CMB observations |
| title | Measuring the Modified Gravitational Wave Propagation beyond General Relativity from CMB Observations |
| title_full | Measuring the Modified Gravitational Wave Propagation beyond General Relativity from CMB Observations |
| title_fullStr | Measuring the Modified Gravitational Wave Propagation beyond General Relativity from CMB Observations |
| title_full_unstemmed | Measuring the Modified Gravitational Wave Propagation beyond General Relativity from CMB Observations |
| title_short | Measuring the Modified Gravitational Wave Propagation beyond General Relativity from CMB Observations |
| title_sort | measuring the modified gravitational wave propagation beyond general relativity from cmb observations |
| topic | primordial gravitational waves modified friction term CMB observations |
| url | https://www.mdpi.com/2218-1997/8/7/367 |
| work_keys_str_mv | AT junli measuringthemodifiedgravitationalwavepropagationbeyondgeneralrelativityfromcmbobservations |