Details
| Original language | English |
|---|---|
| Article number | 056 |
| Journal | Journal of Cosmology and Astroparticle Physics |
| Volume | 2019 |
| Issue number | 1 |
| Publication status | Published - 28 Jan 2019 |
| Externally published | Yes |
Abstract
We derive the most general mimetic scalar-tensor theory assuming a healthy "seed" action and accounting for the constraints on the speed of gravitational-wave propagation arising from the GW170817 event. By analysing linear perturbations around a flat FLRW background in this model, we obtain a suitable form of the Poisson equation, which allows us to calculate the effective gravitational constant felt by "ordinary" matter. By restricting to a minimally coupled model, such an effective gravitational constant is equivalent to that obtained within General Relativity, with cold dark matter plus a perfect fluid dark energy component, with vanishing sound speed. Assuming, further, a ΛCDM background, the effective gravitational constant cannot be distinguished from that of the standard ΛCDM model, at linear order. For the full non-minimally coupled mimetic gravity model we obtain a non-vanishing gravitational slip and an effective gravitational constant which always differs from that of standard ΛCDM .
Keywords
- dark energy theory, modified gravity
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Astronomy and Astrophysics
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In: Journal of Cosmology and Astroparticle Physics, Vol. 2019, No. 1, 056, 28.01.2019.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Gravity in mimetic scalar-tensor theories after GW170817
AU - Ganz, Alexander
AU - Bartolo, Nicola
AU - Karmakar, Purnendu
AU - Matarrese, Sabino
N1 - Funding Information: We warmly acknowledge Frederico Arroja and Dimitri Sorokin for useful discussions. Part of the computations are done using Mathematica4 with the algebra package xAct5 and its contributed package xPand6 [63]. We acknowledge partial financial support by ASI Grant No. 2016-24-H.0. PK acknowledges financial support from “Fondazione Ing. Aldo Gini”.
PY - 2019/1/28
Y1 - 2019/1/28
N2 - We derive the most general mimetic scalar-tensor theory assuming a healthy "seed" action and accounting for the constraints on the speed of gravitational-wave propagation arising from the GW170817 event. By analysing linear perturbations around a flat FLRW background in this model, we obtain a suitable form of the Poisson equation, which allows us to calculate the effective gravitational constant felt by "ordinary" matter. By restricting to a minimally coupled model, such an effective gravitational constant is equivalent to that obtained within General Relativity, with cold dark matter plus a perfect fluid dark energy component, with vanishing sound speed. Assuming, further, a ΛCDM background, the effective gravitational constant cannot be distinguished from that of the standard ΛCDM model, at linear order. For the full non-minimally coupled mimetic gravity model we obtain a non-vanishing gravitational slip and an effective gravitational constant which always differs from that of standard ΛCDM .
AB - We derive the most general mimetic scalar-tensor theory assuming a healthy "seed" action and accounting for the constraints on the speed of gravitational-wave propagation arising from the GW170817 event. By analysing linear perturbations around a flat FLRW background in this model, we obtain a suitable form of the Poisson equation, which allows us to calculate the effective gravitational constant felt by "ordinary" matter. By restricting to a minimally coupled model, such an effective gravitational constant is equivalent to that obtained within General Relativity, with cold dark matter plus a perfect fluid dark energy component, with vanishing sound speed. Assuming, further, a ΛCDM background, the effective gravitational constant cannot be distinguished from that of the standard ΛCDM model, at linear order. For the full non-minimally coupled mimetic gravity model we obtain a non-vanishing gravitational slip and an effective gravitational constant which always differs from that of standard ΛCDM .
KW - dark energy theory
KW - modified gravity
UR - http://www.scopus.com/inward/record.url?scp=85062281822&partnerID=8YFLogxK
U2 - 10.48550/arXiv.1809.03496
DO - 10.48550/arXiv.1809.03496
M3 - Article
AN - SCOPUS:85062281822
VL - 2019
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
SN - 1475-7516
IS - 1
M1 - 056
ER -