Friction in gravitational waves: a test for early-time modified gravity
Modified gravity theories predict in general a non standard equation for the propagation of gravitational waves. Here we discuss the impact of modified friction and speed of tensor modes on cosmic microwave polarization B modes. We show that the non standard friction term, parametrized by $\alpha_{M...
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| Main Authors: | , |
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| Format: | Article (Journal) Chapter/Article |
| Language: | English |
| Published: |
2015
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| In: |
Arxiv
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| Online Access: | Verlag, kostenfrei, Volltext: http://arxiv.org/abs/1408.2224
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| Author Notes: | Valeria Pettorino and Luca Amendola |
| Summary: | Modified gravity theories predict in general a non standard equation for the propagation of gravitational waves. Here we discuss the impact of modified friction and speed of tensor modes on cosmic microwave polarization B modes. We show that the non standard friction term, parametrized by $\alpha_{M}$, is degenerate with the tensor-to-scalar ratio $r$, so that small values of $r$ can be compensated by negative constant values of $\alpha_M$. We quantify this degeneracy and its dependence on the epoch at which $\alpha_{M}$ is different from the standard, zero, value and on the speed of gravitational waves |
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| Item Description: | Gesehen am 10.11.2017 |
| Physical Description: | Online Resource |