General modified gravity with 21cm intensity mapping: simulations and forecast

Heneka, Caroline; Amendola, Luca

doi:10.1088/1475-7516/2018/10/004

Cited by 20 publications

(18 citation statements)

References 52 publications

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“…In the next decade, several large-scale surveys, such as DESI, Euclid, SKA and LSST, are planned to start, and they will cover the entire redshift range over which dark energy played a significant role in the accelerated expansion. Looking forward to having real data, forecasts analysis is improving our knowledge of cosmology by looking at specific gravity models as well as modelindependent parametrizations [37][38][39][40][41]. In this work we provide cosmological constraints on sH theories using both present data sets and future spectroscopic galaxy clustering (GC) and weak lensing (WL) observables.…”

Section: Introductionmentioning

confidence: 99%

Cosmology of surviving Horndeski theory: The road ahead

et al. 2019

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In the context of the effective field theory of dark energy (EFT) we perform agnostic explorations of Horndeski gravity. We choose two parametrizations for the free EFT functions, namely, a power law and a dark energy density-like behavior on a nontrivial Chevallier-Polarski-Linder background. We restrict our analysis to those EFT functions which do not modify the speed of propagation of gravitational waves. Among those, we prove that one specific function cannot be constrained by data since its contribution to the observables is below the cosmic variance, although we show it has a relevant role in defining the viable parameter space. We place constraints on the parameters of these models by combining measurements from present-day cosmological data sets, and we prove that the next-generation galaxy surveys can improve such constraints by 1 order of magnitude. We then prove the validity of the quasistatic limit within the sound horizon of the dark field, by looking at the phenomenological functions μ and Σ, associated, respectively, with clustering and lensing potentials. Furthermore, we notice up to 5% deviations in μ, Σ with respect to general relativity at scales smaller than the Compton one. For the chosen parametrizations and in the quasistatic limit, future constraints on μ and Σ can reach the 1% level and will allow us to discriminate between certain models at more than 3σ, provided the present best-fit values remain.

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Section: Introductionmentioning

confidence: 99%

Cosmology of surviving Horndeski theory: The road ahead

et al. 2019

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“…Compared to similar studies [31,35,[41][42][43], this work includes the following important new aspects: i) we start by mocking realistic 21cm observations that are about to be achieved by present day experiments, once the foregrounds will be removed from the data; ii) we employ a full MCMC Bayesian analysis, rather than adopting a Fisher Matrix approach; iii) we start by considering the present day full CMB data from Planck, rather than assuming priors on cosmological parameters measured; iv) we combine 21cm observations only with CMB data, without considering other probes, to disentangle precisely the constraining power of such future observations; v) we include a conservative treatment of the astrophysical quantities that are used to mock the 21cm power spectrum, like the brightness temperature and the atomic hydrogen bias.…”

Section: Introductionmentioning

confidence: 86%

“…In this work, we focus on the 21cm signal detection through line intensity mapping techniques, which allows to sample the neutral hydrogen (HI) distribution in a wide redshift range [24][25][26][27][28][29]. These observations will open an important window on DE/MG theories [30][31][32][33][34][35][36]. Currently, several purpose-built radiotelescopes, such as the Canadian Hydrogen Intensity Mapping Experiment (CHIME), 1 the Hydrogen Intensity and Real-Time Analysis experiment (HIRAX), 2 the Five-hundred-meter Aperture Spherical Telescope (FAST), 3 are already taking data or are under construction.…”

Section: Introductionmentioning

confidence: 99%

Constraining beyond $Λ$CDM models with 21cm intensity mapping forecast observations combined with latest CMB data

Berti,

Spinelli,

Haridasu

et al. 2021

Preprint

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We explore constraints on dark energy and modified gravity with forecast 21cm intensity mapping measurements using the Effective Field Theory approach. We construct a realistic mock data set forecasting a low redshift 21cm signal power spectrum P 21 (z, k) measurement from the MeerKAT radio-telescope. We compute constraints on cosmological and model parameters through Monte Carlo Markov chain techniques, testing both the constraining power of P 21 (k) alone and its effect when combined with the latest Planck 2018 CMB data. We complement our analysis by testing the effects of tomography from an ideal mock data set of observations in multiple redshift bins. We conduct our analysis numerically with the codes EFTCAMB/EFTCosmoMC, which we extend by implementing a likelihood module fully integrated with original codes. We find that adding P 21 (k) to CMB data provides significantly tighter constraints on Ω c h 2 and H 0 , with a reduction of the error with respect to Planck results at the level of more than 60%. For the parameters describing beyond ΛCDM theories, we observe a reduction in the error with respect to the Planck constraints at the level of 10%. The improvement increases up to ∼ 35% when we constrain the parameters using ideal, tomographic mock observations. We conclude that the power spectrum of the 21cm signal is sensitive to variations of the parameters describing the examined beyond ΛCDM models and, thus, P 21 (k) observations could help to constrain dark energy. The constraining power on such theories is improved significantly by tomography.

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“…Finally, Square Kilometre Array (SKA) mission is proved to be a promising tool to test gravity over a large range of scales and redshifts. [84].…”

Section: R19mentioning

confidence: 99%

Updating constraints on f(T) teleparallel cosmology and the consistency with Big Bang Nucleosynthesis

Benetti,

Capozziello,

Lambiase

2020

Preprint

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We focus on viable f (T ) teleparallel cosmological models, namely power law, exponential and square-root exponential, carrying out a detailed study of their evolution at all scales. Indeed, these models were extensively analysed in the light of late time measurements, while it is possible to find only upper limits looking at the very early time behavior, i.e. satisfying the Big Bang Nucleosynthesis (BBN) data on primordial abundance of 4 He. Starting from these indications, we perform our analysis considering both background and linear perturbations evolution and constrain, beyond the standard six cosmological parameters, the free parameters of f (T ) models in both cases whether the BBN consistency relation is considered or not. We use a combination of Cosmic Microwave Background, Baryon Acoustic Oscillation, Supernovae Ia and galaxy clustering measurements, and find that very narrow constraints on the free parameters of specific f (T ) cosmology can be obtained, beyond any previous precision. While no degeneration is found between the helium fraction, Y P , and the free parameter of f (T ), we note that these models constrain the current Hubble parameter, H 0 , higher then the standard model one, fully compatible with the Riess et al. measurement in the case of power law f (T ) model. Moreover, the free parameters are constrained at nonzero values in more than 3-σ, showing a preference of the observations for extended gravity models.

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General modified gravity with 21cm intensity mapping: simulations and forecast

Cited by 20 publications

References 52 publications

Cosmology of surviving Horndeski theory: The road ahead

Cosmology of surviving Horndeski theory: The road ahead

Constraining beyond $Λ$CDM models with 21cm intensity mapping forecast observations combined with latest CMB data

Updating constraints on f(T) teleparallel cosmology and the consistency with Big Bang Nucleosynthesis

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