Backreaction: directions of progress

Räsänen, Syksy

doi:10.1088/0264-9381/28/16/164008

Cited by 117 publications

(127 citation statements)

References 119 publications

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“…This advantage is clearly explained by Räsänen (2010Räsänen ( , 2011: in the framework of the so-called Newtonian cosmology, as opposed to GR, the backreaction effects are reduced to boundary terms vanishing in the case of the standard periodic boundary conditions. It is stressed by Räsänen (2010Räsänen ( , 2011 that Newtonian gravity does not represent the weak field limit of GR.…”

Section: Averaging Initiatives On the Eve Of Cosmological Backreactiomentioning

confidence: 99%

Second-order Cosmological Perturbations Engendered by Point-like Masses

Brilenkov

Eingorn

2017

ApJ

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In the ΛCDM framework, presenting nonrelativistic matter inhomogeneities as discrete massive particles, we develop the second-order cosmological perturbation theory. Our approach relies on the weak gravitational field limit. The derived equations for the second-order scalar, vector and tensor metric corrections are suitable at arbitrary distances including regions with nonlinear contrasts of the matter density. We thoroughly verify fulfilment of all Einstein equations as well as self-consistency of order assignments. In addition, we achieve logical positive results in the Minkowski background limit. Feasible investigations of the cosmological backreaction manifestations by means of relativistic simulations are also outlined.

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Section: Averaging Initiatives On the Eve Of Cosmological Backreactiomentioning

confidence: 99%

Second-order Cosmological Perturbations Engendered by Point-like Masses

Brilenkov

Eingorn

2017

ApJ

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“…of density perturbations can potentially affect the background expansion of the Universe in a process called "back-reaction" (Räsänen 2011). However, since general back-reaction models preserve statistical homogeneity and isotropy, they cannot be constrained by our analysis.…”

Section: Introductionmentioning

confidence: 99%

Homogeneity and isotropy in the Two Micron All Sky Survey Photometric Redshift catalogue

Alonso

Salvador

Sánchez

et al. 2015

Monthly Notices of the Royal Astronomical Society

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Using the 2MASS Photometric Redshift catalogue we perform a number of statistical tests aimed at detecting possible departures from statistical homogeneity and isotropy in the large-scale structure of the Universe. Making use of the angular homogeneity index, an observable proposed in a previous publication, as well as studying the scaling of the angular clustering and number counts with magnitude limit, we place constraints on the fractal nature of the galaxy distribution. We find that the statistical properties of our sample are in excellent agreement with the standard cosmological model, and that it reaches the homogeneous regime significantly faster than a class of fractal models with dimensions D < 2.75. As part of our search for systematic effects, we also study the presence of hemispherical asymmetries in our data, finding no significant deviation beyond those allowed by the concordance model.

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“…This uni- * E-mail: rodrigo.cuzinatto@unifal-mg.edu.br † E-mail: eduardomessiasdemorais@hotmail.com ‡ E-mail: leogmedeiros@ect.ufrn.br 1 Inhomogeneous cosmological model, such as those in Refs. [10][11][12][13][14][15][16], present alternative explanation to the apparent present-day cosmic acceleration.…”

Section: Introductionmentioning

confidence: 99%

Observational constraints to a unified cosmological model

Cuzinatto

Morais

Medeiros

2016

Astroparticle Physics

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We propose a phenomenological unified model for dark matter and dark energy based on an equation of state parameter w that scales with the arctan of the redshift. The free parameters of the model are three constants: Ω b0 , α and β. Parameter α dictates the transition rate between the matter dominated era and the accelerated expansion period. The ratio β/α gives the redshift of the equivalence between both regimes. Cosmological parameters are fixed by observational data from Primordial Nucleosynthesis (PN), Supernovae of the type Ia (SNIa), Gamma-Ray Bursts (GRB) and Baryon Acoustic Oscillations (BAO). The calibration of the 138 GRB events is performed using the 580 SNIa of the Union2.1 data set and a new set of 79 high-redshift GRB is obtained. The various sets of data are used in different combinations to constraint the parameters through statistical analysis. The unified model is compared to the ΛCDM model and their differences are emphasized. PACS numbers: 95.35.+d, 95.36.+x, 98.80.Es

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Backreaction: directions of progress

Cited by 117 publications

References 119 publications

Second-order Cosmological Perturbations Engendered by Point-like Masses

Second-order Cosmological Perturbations Engendered by Point-like Masses

Homogeneity and isotropy in the Two Micron All Sky Survey Photometric Redshift catalogue

Observational constraints to a unified cosmological model

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