Probing dark energy anisotropy

Appleby, Stephen; Linder, Eric V.

doi:10.1103/physrevd.87.023532

Cited by 55 publications

(41 citation statements)

References 75 publications

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“…In the models (A), the dark energy triggers the anisotropic phase. It has been argued (Appleby & Linder 2013) that next generation surveys will be capable of constraining anisotropies at the 5% level in terms of the anisotropic equation of state, which is a number to keep in mind for comparison with weak lensing.…”

Section: Observational Constraintsmentioning

confidence: 99%

Weak-lensingB-modes as a probe of the isotropy of the universe

Pereira

Pitrou

Uzan

2016

A&A

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Aims. We use the angular power spectrum of B-modes of the weak-lensing shear as a tool for constraining late-time deviations of spatial isotropy in our Universe. Methods. We used the formalism of weak lensing in arbitrary spacetimes. Results. We find that off-diagonal correlations must exist between E-modes, B-modes, and convergence of the weak-lensing field, which allow one to reconstruct the eigendirections of anisotropic expansion. Focusing on future surveys, such as Euclid and the Square Kilometer Array (SKA), we find that observations can constrain the geometrical shear in units of the Hubble rate at the percent level or better. These observations offer a new and powerful method to probe our cosmological model, however, the power of this new technique still requires further investigations and a full analysis of signal-to-noise ratio.

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Section: Observational Constraintsmentioning

confidence: 99%

Weak-lensingB-modes as a probe of the isotropy of the universe

Pereira

Pitrou

Uzan

2016

A&A

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“…4 Then the posterior probability density function that depends only on the cosmological parameters p is given by 1 See, e.g., [11][12][13][14][15][16][17], and [18]; also see [19]. For constraints on these and related models from near-future data see [20][21][22], and references therein. 2 For related work with growth factor data, see [23].…”

Section: A Growth Rate Of Lssmentioning

confidence: 99%

Cosmological constraints from large-scale structure growth rate measurements

2014

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We compile a list of 14 independent measurements of a large-scale structure growth rate between redshifts 0.067 ≤ z ≤ 0.8 and use this to place constraints on model parameters of constant and timeevolving general-relativistic dark energy cosmologies. With the assumption that gravity is well modeled by general relativity, we discover that growth-rate data provide restrictive cosmological parameter constraints. In combination with type Ia supernova apparent magnitude versus redshift data and Hubble parameter measurements, the growth rate data are consistent with the standard spatially flat ΛCDM model, as well as with mildly evolving dark energy density cosmological models.

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“…Similarly, it has been shown that the CMB angular power spectrum has a quadrupole power persistently lower than expected from the best-fit ΛCDM model [42,49,[51][52][53]. Several explanations for this anomaly have been proposed [22-24, 27, 28, 54-60], including the anisotropic expansion of the Universe, that could be developed well after the matter-radiation decoupling, for example, during the domination of DE, say, by means of its anisotropic pressure, acting as a late-time source of not insignificant anisotropy (see, e.g., [23][24][25][26][27][28][29][30][31][32][33][61][62][63][64][65][66] for anisotropic DE models and [67][68][69][70] for constraint studies on the anisotropic DE). On the other hand, in GR in the absence of any anisotropic source as it is the case in the standard ΛCDM, the CMB provides very tight constraints on the anisotropy at the time of recombination arXiv:1905.06949v2 [astro-ph.CO] 24 Jul 2019 [71][72][73] of the order of the quadrupole temperature fluctuation (∆T /T ) =2 ∼ 10 −5 .…”

Section: Introductionmentioning

confidence: 99%

Constraints on a Bianchi type I spacetime extension of the standard ΛCDM model

et al. 2019

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We consider the simplest anisotropic generalization, as a correction, to the standard ΛCDM model, by replacing the spatially flat Robertson-Walker metric by the Bianchi type-I metric, which brings in a new term Ωσ0a −6 (mimicking the stiff fluid) in the average expansion rate H(a) of the Universe. From Hubble and Pantheon data, relevant to the late Universe (z 2.4), we obtain the constraint Ωσ0 10 −3 , in line with the model-independent constraints. When the baryonic acoustic oscillations and cosmic microwave background (CMB) data are included, the constraint improves by 12 orders of magnitude, i.e., Ωσ0 10 −15 . We find that this constraint could alter neither the matter-radiation equality redshift nor the peak of the matter perturbations. Demanding that the expansion anisotropy has no significant effect on the standard big bang nucleosynthesis (BBN), we find the constraint Ωσ0 10 −23 . We show explicitly that the constraint from BBN renders the expansion anisotropy irrelevant to make a significant change in the CMB quadrupole temperature, whereas the constraint from the cosmological data in our model provides the temperature change up to ∼ 11 mK, though it is much beyond the CMB quadrupole temperature.

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Probing dark energy anisotropy

Cited by 55 publications

References 75 publications

Weak-lensingB-modes as a probe of the isotropy of the universe

Weak-lensingB-modes as a probe of the isotropy of the universe

Cosmological constraints from large-scale structure growth rate measurements

Constraints on a Bianchi type I spacetime extension of the standard ΛCDM model

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