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We present a formalism to calculate the non-linear matter power spectrum in modified gravity models that explain the late-time acceleration of the Universe without dark energy. Any successful modified gravity models should contain a…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-03 Kazuya Koyama , Atsushi Taruya , Takashi Hiramatsu

Weak lensing surveys are often summarized by constraints on the derived parameter ${S_8\equiv\sigma_8\sqrt{\Omega_{\rm m}/0.3}}$, obscuring the rich scale and redshift information encoded in the data, and limiting our ability to identify…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-08 Cyrille Doux , Tanvi Karwal

We observationally examine cosmological models based on primordial power spectra with quantized wavevectors. Introducing a linearly quantized power spectrum with $k_0=3.225\times10^{-4}\mathrm{Mpc}^{-1}$ and spacing $\Delta k = 2.257 \times…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-18 D. J. Bartlett , W. J. Handley , A. N. Lasenby

The Cosmic Microwave Background Radiation (CMBR) holds information about almost all the fundamental cosmological parameters, and by performing a likelihood analysis of high precision CMBR fluctuation data, these parameters can be inferred.…

Astrophysics · Physics 2009-10-31 Steen Hannestad

Precision measurements of the galaxy power spectrum P(k) require a data analysis pipeline that is both fast enough to be computationally feasible and accurate enough to take full advantage of high-quality data. We present a rigorous…

Astrophysics · Physics 2009-10-07 Max Tegmark , Andrew Hamilton , Michael Strauss , Michael Vogeley , Alexander Szalay

When it comes to searches for extensions to general relativity, large efforts are being dedicated to accurate predictions for the power spectrum of density perturbations. While this observable is known to be sensitive to the gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-08 Claudio Llinares , Nuala McCullagh

The large-scale structure growth index $\gamma$ provides a consistency test of the standard cosmology and is a potential indicator of modified gravity. We investigate the constraints on $\gamma$ from next-generation spectroscopic surveys,…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-12 José Fonseca , Jan-Albert Viljoen , Roy Maartens

We investigate the impact on cosmological observables of $f(Q)$-gravity, a specific class of modified gravity models in which gravity is described by the non-metricity scalar, $Q$. In particular we focus on a specific model which is…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-24 Noemi Frusciante

We present an interpretable emulator for the linear matter power spectrum (MPS) in the standard cosmological model $\Lambda$CDM, constructed via a physics-informed symbolic regression framework. By combining domain knowledge with a machine…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-12 J. Bayron Orjuela-Quintana , Domenico Sapone , Savvas Nesseris

In a mean-field approximation within Kinetic Field Theory, it is possible to derive an accurate analytic expression for the power spectrum of present-day non-linear cosmic density fluctuations. It depends on the theory of gravity and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-13 Alexander Oestreicher , Harshda Saxena , Niklas Reinhardt , Elena Kozlikin , Johannes Dombrowski , Matthias Bartelmann

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

We estimate the sensitivity of future galaxy surveys to cosmological parameters, using the redshift dependent angular power spectra of galaxy number counts, $C_\ell(z_1,z_2)$, calculated with all relativistic corrections at first order in…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-04 Enea Di Dio , Francesco Montanari , Ruth Durrer , Julien Lesgourgues

The angular power spectra of cosmic microwave background are analyzed under the light of the evolutional scenario of the universe based on the renormalizable quantum theory of gravity in four dimensions. The equation of evolution is solved…

Astrophysics · Physics 2009-11-13 Ken-ji Hamada , Shinichi Horata , Naoshi Sugiyama , Tetsuyuki Yukawa

Current and coming surveys will require sub-percent agreement in theoretical accuracy to test the different cosmological and gravity scenarios. This can be performed with Boltzmann solvers, i.e. codes that solve the linear evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2020-10-13 Rubén Arjona

We present a general method to compute the nonlinear matter power spectrum for dark energy and modified gravity scenarios with percent-level accuracy. By adopting the halo model and nonlinear perturbation theory, we predict the reaction of…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-16 Matteo Cataneo , Lucas Lombriser , Catherine Heymans , Alexander Mead , Alexandre Barreira , Sownak Bose , Baojiu Li

Modified gravity provides a possible explanation for the currently observed cosmic accelaration. In this paper, we study general classes of modified gravity models. The Einstein-Hilbert action is modified by using general functions of the…

Astrophysics · Physics 2008-11-26 Antonio De Felice , Pia Mukherjee , Yun Wang

Modifications on the predictions about the matter power spectrum based on the hypothesis of a tiny contribution from a degenerate Fermi gas (DFG) test-fluid to some dominant cosmological scenario are investigated. Reporting about the…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 E. L. D. Perico , Alex E. Bernardini

Direct measurements of the matter power spectrum, $P_\mathrm{m}(k,z)$, provide a powerful tool to investigate observed tensions between models of structure growth while also testing the internal consistency of cosmological probes. We…

The combination of multiple cosmological probes can produce measurements of cosmological parameters much more stringent than those possible with any individual probe. We examine the combination of two highly correlated probes of late-time…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-08 Donnacha Kirk , Ofer Lahav , Sarah Bridle , Stephanie Jouvel , Filipe B. Abdalla , Joshua A. Frieman

The recent measurements of Cosmic Microwave Background temperature and polarization anisotropies made by the Planck satellite have provided impressive confirmation of the $\Lambda$CDM cosmological model. However interesting hints of slight…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Eleonora Di Valentino , Alessandro Melchiorri , Joseph Silk