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We investigate the evolution of matter density perturbations within a fractional cosmological framework inspired by fractal space-time constructions in field theory, where a deformation of the integration measure induces non-locality and…

General Relativity and Quantum Cosmology · Physics 2026-04-24 S. M. M. Rasouli

We present a new measurement of structure growth at $z \simeq 0.08$ obtained by correlating the cosmic microwave background (CMB) lensing potential map from the \textit{Planck} satellite with the angular distribution of the 2MASS…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-08 Federico Bianchini , Christian L. Reichardt

On the basis of a previously established scalar-tensor extension of the $\Lambda$CDM model we develop an effective fluid approach for the matter growth function. This extended $\Lambda$CDM (henceforth $e_{\Phi}\Lambda$CDM) cosmology takes…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 W. Zimdahl , H. E. S. Velten , W. C. Algoner

The low statistical errors on cosmological parameters promised by future galaxy surveys will only be realised with the development of new, fast, analysis methods that reduce potential systematic problems to low levels. We present an…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-23 Rossana Ruggeri , Will Percival , Héctor Gil-Marín , Fangzhou Zhu , Gongbo Zhao , Yuting Wang

We present a methodology for constructing modified gravity (MG) constrained simulations of the local Universe using positions and peculiar velocities from the CosmicFlows data set. Our analysis focuses on the following MG models: the normal…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-27 Krishna Naidoo , Wojciech A. Hellwing , Maciej Bilicki , Noam Libeskind , Simon Pfeifer , Yehuda Hoffman

We consider the cosmological implications of a four-dimensional extension of the Gauss-Bonnet $f(G)$ gravity, where $G$ is the Gauss-Bonnet topological invariant, in which the Einstein-Hilbert action is replaced by an arbitrary function…

General Relativity and Quantum Cosmology · Physics 2025-06-23 Ratul Mandal , Himanshu Chaudhary , Tiberiu Harko , Ujjal Debnath , G. Mustafa

We consider a modified gravity model with a running gravitational constant coupled to a varying dark energy fluid and test its imprint on the growth of structure in the universe. Using Redshift Space Distortion (RSD) measurement results, we…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-20 Tilek Zhumabek , Azamat Mukhamediya , Hrishikesh Chakrabarty , Daniele Malafarina

Current cosmological observations allow for deviations from the standard growth of large-scale structures in the universe. These deviations could indicate modifications to General Relativity on cosmological scales or suggest the dynamical…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-12 Yo Toda , Adrià Gómez-Valent , Kazuya Koyama

We study cosmological models with modified Chaplygin gas (in short, MCG) to determine observational constraints on its EoS parameters. The observational data of the background and the growth tests are employed. The background test data…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-02 Bikash Chandra Paul , Prasenjit Thakur , Aroonkumar Beesham

Teleparallel gravity offers a competing geometric framework on which to build cosmological models. The Gauss-Bonnet invariant captures key aspects of the underlying geometry that has been shown to be an interesting way to form cosmological…

General Relativity and Quantum Cosmology · Physics 2026-03-03 Shivam Kumar Mishra , Jackson Levi Said , B. Mishra

The growth index $\gamma_L$ was proposed to investigate the possible deviation from the standard $\Lambda$CDM model and Einstein's gravity theory in a dynamical perspective. Recently, thanks to the measurement of the cosmic growth rate via…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-01 Lixin Xu

The bulk motion of galaxies induced by the growth of cosmic structure offers a rare opportunity to test the validity of general relativity across cosmological scales. However, modified gravity can be degenerate in its effect with the…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-02 Fergus Simpson , John A. Peacock

Possible explanations of the observed accelerated expansion of the Universe are the introduction of a dark energy component or the modifications of gravity at large distances. A particular difference between these scenarios is the dynamics…

Astrophysics · Physics 2007-05-23 Jia-Yu Tang , Jochen Weller , Alan Zablocki

The consideration of a 1 + 3 covariant approach to cold dark matter universe with no shear cosmological dust model with irrotational flows is developed in the context of f (G) gravity theory in the present study. This approach reveals the…

General Relativity and Quantum Cosmology · Physics 2023-05-19 Albert Munyeshyaka , Joseph Ntahompagaze , Tom Mutabazi , Manasse. R Mbonye

Cosmic voids in the large-scale structure of the Universe affect the peculiar motions of objects in their vicinity. Although these motions are difficult to observe directly, the clustering pattern of their surrounding tracers in redshift…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-01 Nico Hamaus , P. M. Sutter , Guilhem Lavaux , Benjamin D. Wandelt

Cosmological constraints of Modified Gravity (MG) models are seldom carried out rigorously. First, even though general MG models evolve differently (i.e., background and perturbations) to the standard cosmological model, it is usual to…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-27 Wilmar Cardona , Rubén Arjona , Alejandro Estrada , Savvas Nesseris

In the last dozen years a wide and variegated mass of observational data revealed that the universe is now expanding at an accelerated rate. In the absence of a well-based theory to interpret the observations, cosmography provides…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Ester Piedipalumbo , Enrica Della Moglie , Roberto Cianci

Cosmological structures grow differently in theories of gravity which are modified as compared to Einstein's General relativity (GR). Cosmic microwave background (CMB) fluctuation patterns at the last scattering surface are lensed by these…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-12 Toshiya Namikawa , François R. Bouchet , Atsushi Taruya

We explore the influences of the higher order Gauss Bonnet (GB) correction terms on the growth of perturbations at the early stage of a (n + 1)-dimensional Friedmann-Robertson-Walker (FRW) universe. Considering a cosmological constant in…

General Relativity and Quantum Cosmology · Physics 2024-12-17 Ahmad Sheykhi , Bita Farsi

Combining measurements on the expansion history of the Universe and on the growth rate of cosmic structures is key to discriminate between alternative cosmological frameworks and to test gravity. Recently, Linder (2017) proposed a new…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-16 Michele Moresco , Federico Marulli
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