Constraints on Galileons from the positions of supermassive black holes

Bartlett, Deaglan J.; Desmond, Harry; Ferreira, Pedro G.

doi:10.1103/physrevd.103.023523

Cited by 22 publications

(29 citation statements)

References 105 publications

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“…7 (a)). Subsequent work has verified using hydrodynamical simulations that the baryonic noise model used in these analyses is accurate [185]. 10 −8 is around the lowest Newtonian potential probed by any astrophysical object, so it will be very hard to reach lower values of f R0 .…”

Section: B Galaxy and Void Testsmentioning

confidence: 96%

“…where ∇Φ ext N is the unscreened large-scale gravitational field, proportional to the galileon fifth-force field. Bartlett et al [192] modelled this field using constrained N-body simulations of the local ∼200 Mpc and forward-modelled the offsets in 1916 galaxies with AGN, including a more sophisticated model for the halo density profiles, to set the bound β < 0.28 for r c > ∼ 1/H 0 (see Fig. 7 (b)).…”

Section: B Galaxy and Void Testsmentioning

confidence: 99%

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Testing Screened Modified Gravity

Brax¹,

Casas²,

Desmond³

et al. 2022

Preprint

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Long range scalar fields with a coupling to matter appear to violate known bounds on gravitation in the solar system and the laboratory. This is evaded thanks to screening mechanisms. In this short review, we shall present the various screening mechanisms from an effective field theory point of view. We then investigate how they can and will be tested in the laboratory and on astrophysical and cosmological scales.

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Section: B Galaxy and Void Testsmentioning

confidence: 96%

Section: B Galaxy and Void Testsmentioning

confidence: 99%

Testing Screened Modified Gravity

Brax¹,

Casas²,

Desmond³

et al. 2022

Preprint

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show abstract

“…Novel sophisticated additions to the forward model include a robust likelihood to account for unknown foreground contamination and systematics (Porqueres et al 2019b) and machine learning-based galaxy bias models (Charnock et al 2020). The reconstructed density and velocity fields from Borg analyses have been employed in investigating extensions of the standard model of particle physics and cosmology (Desmond et al 2018(Desmond et al , 2019Pardo et al 2019;Desmond & Ferreira 2020;Bartlett et al 2021) and for unbiased and accurate measurements of the Hubble constant from gravitational wave events (Mukherjee et al 2021), as well as those of the kinematic Sunyaev-Zel'dovich effect from CMB observations (Nguyen et al 2020).…”

Section: Appendix A: 2m++ Galaxy Catalogmentioning

confidence: 99%

Optimal machine-driven acquisition of future cosmological data

Kostić

Jasche

Ramanah

et al. 2022

A&A

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We present a set of maps classifying regions of the sky according to their information gain potential as quantified by Fisher information. These maps can guide the optimal retrieval of relevant physical information with targeted cosmological searches. Specifically, we calculated the response of observed cosmic structures to perturbative changes in the cosmological model and we charted their respective contributions to Fisher information. Our physical forward-modeling machinery transcends the limitations of contemporary analyses based on statistical summaries to yield detailed characterizations of individual 3D structures. We demonstrate this advantage using galaxy counts data and we showcase the potential of our approach by studying the information gain of the Coma cluster. We find that regions in the vicinity of the filaments and cluster core, where mass accretion ensues from gravitational infall, are the most informative with regard to our physical model of structure formation in the Universe. Hence, collecting data in those regions would be most optimal for testing our model predictions. The results presented in this work are the first of their kind to elucidate the inhomogeneous distribution of cosmological information in the Universe. This study paves a new way forward for the performance of efficient targeted searches for the fundamental physics of the Universe, where search strategies are progressively refined with new cosmological data sets within an active learning framework.

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“…We can rephrase our problem so that this is not an issue. Let us decompose the gravitational 1 A set of 100 dark matter-only simulations based on the 2M++ reconstruction, dubbed CSiBORG [36], is also available. This could be used to access smaller scales because the initial conditions are augmented with white noise.…”

Section: B Calculating the Shapiro Time Delaymentioning

confidence: 99%

Constraints on Equivalence Principle Violation from Gamma Ray Bursts

Bartlett,

Bergsdal,

Desmond

et al. 2021

Preprint

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Theories of gravity that obey the Weak Equivalence Principle have the same Parametrised Post-Newtonian parameter γ for all particles at all energies. The large Shapiro time delays of extragalactic sources allow us to put tight constraints on differences in γ between photons of different frequencies from spectral lag data, since a non-zero ∆γ would result in a frequency-dependent arrival time. The majority of previous constraints have assumed that the Shapiro time delay is dominated by a few local massive objects, although this is a poor approximation for distant sources. In this work we consider the cosmological context of these sources by developing a source-by-source, Monte Carlo-based forward model for the Shapiro time delays by combining constrained realisations of the local density field using the BORG algorithm with unconstrained large-scale modes. Propagating uncertainties in the density field reconstruction and marginalising over an empirical model describing other contributions to the time delay, we use spectral lag data of Gamma Ray Bursts from the BATSE satellite to constrain ∆γ < 3.4 × 10 −15 at 1σ confidence between photon energies of 25 keV and 325 keV.

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Constraints on Galileons from the positions of supermassive black holes

Cited by 22 publications

References 105 publications

Testing Screened Modified Gravity

Testing Screened Modified Gravity

Optimal machine-driven acquisition of future cosmological data

Constraints on Equivalence Principle Violation from Gamma Ray Bursts

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