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We study the main cosmological properties of the Generalized Chaplygin Gas (GCG) dark energy model at the background and perturbation levels. By using the latest cosmological data in both the background and perturbation levels, we implement…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 S. F. Salahedin , M. Malekjani , K. Y. Roobiat , R. Pazhouhesh

A type of exponential correction to General Relativity gives viable modified gravity model of dark energy. The model behaves as $R-2\Lambda$ at large curvature where an effective cosmological constant appears, but it becomes zero in flat…

General Relativity and Quantum Cosmology · Physics 2022-01-13 L. N. Granda

We derive the analytic formula of the growth index for $f(R)$ dark energy model where the effect on the growth of matter density perturbation $\delta_m$ from modified gravity (MG) is encoded in the effective Newton coupling constant $G_{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Qing-Guo Huang

We derive the evolution equation of growth factor for the matter over-dense perturbation in $f(T)$ gravity. For instance, we investigate its behavior in power law model at small redshift and compare it to the prediction of $\Lambda$CDM and…

General Relativity and Quantum Cosmology · Physics 2011-03-07 Rui Zheng , Qing-Guo Huang

Using stochastic conformal mapping techniques we study the patterns emerging from Laplacian growth with a power-law decaying threshold for growth $R_N^{-\gamma}$ (where $R_N$ is the radius of the $N-$ particle cluster). For $\gamma > 1$ the…

Statistical Mechanics · Physics 2009-11-10 H. G. E. Hentschel , M. N. Popescu , F. Family

We perform parametric tests of the consistency of the standard $w$CDM model in the framework of general relativity by carefully separating information between the geometry and growth of structure. We replace each late-universe parameter…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-09 Eduardo J. Ruiz , Dragan Huterer

Spatial variations in the distribution of galaxy luminosities, estimated from redshifts as distance proxies, are correlated with the peculiar velocity field. Comparing these variations with the peculiar velocities inferred from galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-08 Martin Feix , Adi Nusser , Enzo Branchini

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

Generative models of graphs based on discrete Denoising Diffusion Probabilistic Models (DDPMs) offer a principled approach to molecular generation by systematically removing structural noise through iterative atom and bond adjustments.…

Machine Learning · Computer Science 2025-11-03 Matteo Ninniri , Marco Podda , Davide Bacciu

A wide range of models describing modifications to General Relativity have been proposed, but no fundamental parameter set exists to describe them. Similarly, no fundamental theory exists for dark energy to parameterize its potential…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-27 Viviana Acquaviva , Eric Gawiser

The cosmological constant $\Lambda$ and cold dark matter (CDM) model ($\Lambda\text{CDM}$) is one of the pillars of modern cosmology and is widely used as the de facto theoretical model by current and forthcoming surveys. As the nature of…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-08 Rubén Arjona , Alessandro Melchiorri , Savvas Nesseris

We constrain the growth index $\gamma$ by performing a full-shape analysis of the power spectrum multipoles measured from the BOSS DR12 data. We adopt a theoretical model based on the Effective Field theory of the Large Scale Structure…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-13 Chiara Moretti , Maria Tsedrik , Pedro Carrilho , Alkistis Pourtsidou

Constraints on the linear growth rate, $f\sigma_8$, using small scale redshift space distortion measurements have a significant statistical advantage over those made on large scales. However, these measurements need to carefully disentangle…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-16 Michael J. Chapman , Zhongxu Zhai , Will J. Percival

We present the first application of a "multiple-tracer" redshift-space distortion (RSD) analysis to an observational galaxy sample, using data from the Galaxy and Mass Assembly survey (GAMA). Our dataset is an r < 19.8 magnitude-limited…

A recently developed linear algebraic method for the computation of perturbation expansion coefficients to large order is applied to the problem of a hydrogenic atom in a magnetic field. We take as the zeroth order approximation the $D…

chem-ph · Physics 2009-10-22 Timothy C. Germann , Dudley R. Herschbach , Bruce M. Boghosian

We study the evolution of matter density perturbations in Galileon cosmology where the late-time cosmic acceleration can be realized by a field kinetic energy. We obtain full perturbation equations at linear order in the presence of five…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-23 Antonio De Felice , Ryotaro Kase , Shinji Tsujikawa

We investigate the cosmological evolution of mimetic matter model with arbitrary scalar potential. The cosmological reconstruction, which is the way to construct a model for arbitrary evolutions of the scale factor, is explicitly done for…

General Relativity and Quantum Cosmology · Physics 2015-04-01 Jiro Matsumoto , Sergei D. Odintsov , Sergey V. Sushkov

We investigate the matter density perturbation $\delta_m$ and power spectrum $P(k)$ in the running vacuum model (RVM) with the cosmological constant being a function of the Hubble parameter, given by $\Lambda = \Lambda_0 + 6 \sigma H H_0+…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-09 Chao-Qiang Geng , Chung-Chi Lee

We compare observational data of growth rate with the prediction by Galileon theory. For the same value of the energy density parameter $\Omega_{m,0}$, the growth rate in Galileon models is enhanced compared with the $\Lambda$CDM case, due…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Koichi Hirano , Zen Komiya

Upcoming ground and space-based experiments may have sufficient accuracy to place significant constraints upon high-redshift star formation, Reionization, and dark matter (DM) using the global 21-cm signal of the intergalactic medium. In…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-04 Joshua J. Hibbard , Jordan Mirocha , David Rapetti , Neil Bassett , Jack O. Burns , Keith Tauscher