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Related papers: Maximum turnaround radius in $f(R)$ gravity

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The maximum size of a cosmic structure is given by the maximum turnaround radius -- the scale where the attraction due to its mass is balanced by the repulsion due to dark energy. We derive generic formulae for the estimation of the maximum…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-17 Sourav Bhattacharya , Konstantinos F. Dialektopoulos , Antonio Enea Romano , Constantinos Skordis , Theodore N. Tomaras

We investigate the turnaround radius in the spherical collapse model, both in General Relativity and in modified gravity, in particular $f(R)$ scenarios. The phases of spherical collapse are marked by the density contrast in the instant of…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Rafael C. C. Lopes , Rodrigo Voivodic , Luis Raul Abramo , Laerte Sodré

We consider the phantom braneworld model in the context of the maximum turn around radius, $R_{\rm TA,max}$, of a stable, spherical cosmic structure with a given mass. The maximum turn around radius is the point where the attraction due to…

General Relativity and Quantum Cosmology · Physics 2017-11-15 Sourav Bhattacharya , Stefanos R Kousvos

We revisit the concept of turnaround radius in cosmology, in the context of modified gravity. While preliminary analyses were limited to scalar-tensor/$F(R)$ gravity, we extend the definition and the study of this quantity to a much broader…

General Relativity and Quantum Cosmology · Physics 2018-07-11 Shin'ichi Nojiri , Sergei D. Odintsov , Valerio Faraoni

In an accelerating universe in General Relativity there is a maximum radius above which a shell of test particles cannot collapse, but is dispersed by the cosmic expansion. This radius could be used in conjunction with observations of large…

General Relativity and Quantum Cosmology · Physics 2015-11-05 Valerio Faraoni

Our intuitive understanding of cosmic structure formation works best in scales small enough so that bound, relaxed gravitating systems are no longer adjusting their radius; and large enough so that space and matter follow the average…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Vasiliki Pavlidou , Theodore N. Tomaras

The maximum allowable size of a spherical cosmic structure as a function of its mass is determined by the maximum turn around radius $R_{\rm TA,max}$, the distance from its centre where the attraction on a radial test particle due to the…

General Relativity and Quantum Cosmology · Physics 2017-08-14 Sourav Bhattacharya , Theodore N Tomaras

Three simple idealised models are studied in order to develop some intuition about the leading order effect of non-sphericity on the maximum turnaround size $R_{\rm TA,max}$ of large scale bound cosmic structures. Two of them describe…

General Relativity and Quantum Cosmology · Physics 2021-03-09 Sourav Bhattacharya , Theodore N Tomaras

We investigate the relationship between the turnaround radius ($R_t$) and the virial mass ($M_v$) of cosmic structures in the context of $\Lambda$CDM model and in an $f(R)$ model of modified gravity -- namely, the Hu-Sawicki model. The…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-24 Rafael C. C. Lopes , Rodrigo Voivodic , L. Raul Abramo , Laerte Sodré

In $\Lambda$CDM cosmology, structure formation is halted shortly after dark energy dominates the mass/energy budget of the Universe. A manifestation of this effect is that in such a cosmology the turnaround radius has an upper bound.…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 Dimitrios Tanoglidis , Vasiliki Pavlidou , Theodore Tomaras

We explore the viable $f(R)$ gravity models in FLRW backgrounds with a free spatial curvature parameter $\Omega_{K}$. In our numerical calculation, we concentrate on the exponential $f(R)$ model of $f(R) = R - \lambda…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-18 Chao-Qiang Geng , Yan-Ting Hsu , Jhih-Rong Lu

Modeling of matter bounce in $f(R,T)$ gravity has been presented with no violation of the null energy condition. Only a closed universe with negative pressure is allowed in good agreement with some recent observations which favor a universe…

General Relativity and Quantum Cosmology · Physics 2022-06-22 Vinod Kumar Bhardwaj , Anirudh Pradhan , Nasr Ahmed , A. A. Shaker

We use N-body simulations to examine whether a characteristic turnaround radius, as predicted from the spherical collapse model in a $\rm {\Lambda CDM}$ Universe, can be meaningfully identified for galaxy clusters, in the presence of full…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-28 Giorgos Korkidis , Vasiliki Pavlidou , Konstantinos Tassis , Evangelia Ntormousi , Theodore N. Tomaras , Konstantinos Kovlakas

In the metric approach of $f(R)$ theories of gravity, the fourth-order field equations are often recast as effective Einstein equations in the presence of standard matter and a curvature fluid (which gathers all the extra terms), always in…

General Relativity and Quantum Cosmology · Physics 2020-12-01 Juan M. Z. Pretel , Sergio E. Jorás , Ribamar R. R. Reis

We reconcile seemingly conflicting statements in the literature about the behavior of cosmological solutions in modified theories of gravity where the Einstein-Hilbert Lagrangian for gravity is modified by the addition of a function of the…

Astrophysics · Physics 2008-11-26 Ignacy Sawicki , Wayne Hu

In the present work we study a concrete model of Scalar--Tensor theory of gravity characterized by two free parameters, and compare its predictions against observational data and constraints coming from supernovae, solar system tests as…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-14 Grigoris Panotopoulos , Angel Rincon

The turnaround radius of a large structure in an accelerating universe has been studied only for spherical structures, while real astronomical systems deviate from spherical symmetry. We show that, for small deviations from spherical…

General Relativity and Quantum Cosmology · Physics 2019-07-16 Andrea Giusti , Valerio Faraoni

We determine the relationship between the turnaround radius, $R_{\rm t}$, and mass, $M_{\rm t}$, in $\Lambda$CDM, and in dark energy scenarios, using an extended spherical collapse model taking into account the effects of shear and…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-27 Antonino Del Popolo , Man Ho Chan , David F. Mota

Applying the definition of the turnaround radius and the fact that the best agreement with observational data on extragalactic scales is currently provided by general relativity with the cosmological constant we consider the behaviour of…

General Relativity and Quantum Cosmology · Physics 2025-03-26 Oleg Zenin , Stanislav Alexeyev

In many cosmological models, including the $\Lambda$CDM concordance model, there exist a theoretical upper bounds on the size of collapsing structures. The most common formulations in the literature refer to a turnaround radius in spherical…

General Relativity and Quantum Cosmology · Physics 2022-05-11 Jan J. Ostrowski , Ismael Delgado Gaspar
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