Numerical solutions to Einstein’s equations in a shearing-dust universe: a code comparison

Adamek, Julian; Barrera-Hinojosa, Cristian; Bruni, Marco; Li, Baojiu; MacPherson, H.; Mertens, James B.

doi:10.1088/1361-6382/ab939b

Cited by 17 publications

(15 citation statements)

References 103 publications

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“…This means we will neglect terms that are quadratic in B i and also approximate e φ B i ≃ e ψ B i ≃ B i . A comparison with numerical relativity simulations (Adamek et al 2020) demonstrates that this is an extremely good approximation. The spin-2 field h ij , which is transverse and traceless, is even smaller on the scales that we are interested in, and we will therefore neglect it here.…”

Section: Optical Equations In Poisson Gaugementioning

confidence: 75%

Weak-lensing observables in relativistic N-body simulations

Lepori

Adamek

Durrer

et al. 2020

Monthly Notices of the Royal Astronomical Society

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Abstract We present a numerical weak-lensing analysis that is fully relativistic and non-perturbative for the scalar part of the gravitational potential and first-order in the vector part, frame dragging. Integrating the photon geodesics backwards from the observer to the emitters, we solve the Sachs optical equations and study in detail the weak-lensing convergence, ellipticity and rotation. For the first time, we apply such an analysis to a high-resolution relativistic N-body simulation, which consistently includes the leading-order corrections due to general relativity on both large and small scales. These are related to the question of gauge choice and to post-Newtonian corrections, respectively. We present the angular power spectra and one-point probability distribution functions for the weak-lensing variables, which we find are broadly in agreement with comparable Newtonian simulations. Our geometric approach, however, is more robust and flexible, and can therefore be applied consistently to non-standard cosmologies and modified theories of gravity.

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Section: Optical Equations In Poisson Gaugementioning

confidence: 75%

Weak-lensing observables in relativistic N-body simulations

Lepori

Adamek

Durrer

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…On the other hand, particle-based modeling is adopted at the price of using the weak-field expansion of Einstein's equations (Adamek et al 2019). However, codes that adopt a particle description alongside numerical relativity (East et al 2018;Giblin et al 2019;Daverio et al 2019), including the recent code GRAMSES (Barrera-Hinojosa & Li 2020a,b), are set to provide important progress toward a definitive answer to the questions raised by the backreaction proposal (Adamek et al 2020).…”

Section: A Historical Note On Ltb Void Modelsmentioning

confidence: 99%

The BEHOMO project: Λ Lemaître-Tolman-Bondi N-body simulations

Marra

Castro

Camarena

et al. 2022

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Context. Our universe may feature large-scale inhomogeneities and anisotropies that cannot be explained by the standard model of cosmology, that is, the homogeneous and isotropic Friedmann-Lemaître-Robertson-Walker metric, on which the Λ cold dark matter model is built, may not accurately describe observations. Currently, there is not a satisfactory understanding of the evolution of the large-scale structure on an inhomogeneous background. Aims. We have launched the cosmology beyond homogeneity and isotropy (BEHOMO) project to study the inhomogeneous Λ Lemaître-Tolman-Bondi model with the methods of numerical cosmology. Understanding the evolution of the large-scale structure is a necessary step in constraining inhomogeneous models with present and future observables and placing the standard model on more solid ground. Methods. We perform Newtonian N -body simulations, whose accuracy in describing the background evolution is checked against the general relativistic solution. The large-scale structure of the corresponding Λ cold dark matter simulation is also validated. Results. We obtain the first set of simulations of the Λ Lemaître-Tolman-Bondi model ever produced. The data products consist of 11 snapshots between redshift 0 and 3.7 for each of the 68 simulations that have been performed, together with halo catalogs and lens planes relative to 21 snapshots, between redshift 0 and 4.2, for a total of approximately 180 TB of data. Conclusions. We plan to study the growth of perturbations at the linear and nonlinear level, gravitational lensing, and cluster abundances and proprieties. Data can be obtained upon request. Further information is available at valeriomarra.github.io/BEHOMO-project.

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“…NRPy (http: //astro.phys.wvu.edu/bhathome) (Ruchlin et al, 2018) is a code aimed for use on non-HPC systems, which generate C code from Python, and uses adapted coordinate systems to minimise computational costs. CosmoGRaPH (https://cwru-pat.github.io/cosmograph) (Mertens et al, 2016) and GRAMSES (Barrera-Hinojosa & Li, 2020) are among several NR codes targeted at cosmological applications (see (Adamek et al, 2020) for a comparison) and which also employ particle methods. Simflowny (https://bitbucket.org/iac3/simflowny/wiki/Home) (Palenzuela et al, 2018), like CosmoGRaPH, is based on the SAMRAI infrastructure, and has targeted fluid and MHD applications.…”

Section: Statement Of Needmentioning

confidence: 99%