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We study how well perturbative forward modeling can constrain cosmological parameters compared to conventional analyses. We exploit the fact that in perturbation theory the field-level posterior can be computed analytically in the limit of…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-31 Giovanni Cabass , Marko Simonović , Matias Zaldarriaga

We reconstruct the non-linear matter power spectrum $P(k)$ using a joint analysis of gravitational lensing of the cosmic microwave background (CMB) and lensing of galaxies. This reconstruction is motivated by the $S_8$ tension between…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-11 Karen Perez Sarmiento , Alex Laguë , Mathew Madhavacheril , Bhuvnesh Jain , Blake Sherwin

Generally, natural scientific problems are so complicated that one has to establish some effective perturbation or nonperturbation theories with respect to some associated ideal models. In this Letter, a new theory that combines…

Computational Physics · Physics 2015-05-13 Yuan Gao , S. Y. Lou

We apply a non-linear statistical method in turbulence to the cosmological perturbation theory and derive a closed set of evolution equations for matter power spectra. The resultant closure equations consistently recover the one-loop…

Astrophysics · Physics 2009-11-13 Atsushi Taruya , Takashi Hiramatsu

We measure the covariance of the non-linear matter power spectrum from N-body simulations using two methods. In the first case, the covariance of power is estimated from the scatter over many random realizations of the density field. In the…

Astrophysics · Physics 2009-11-11 C. D. Rimes , A. J. S. Hamilton

In the era of high precision CMB measurements, systematic effects are beginning to limit the ability to extract subtler cosmological information. The non-circularity of the experimental beam has become progressively important as CMB…

Astrophysics · Physics 2011-04-11 Tarun Souradeep , Sanjit Mitra , Anand Sengupta , Subharthi Ray , Rajib Saha

We propose a method of calculation of the power spectrum of cosmological perturbations by means of a direct numerical integration of hydrodynamic equations in the Fourier space for a random ensemble of initial conditions with subsequent…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-27 V. M. Sliusar , V. I. Zhdanov

Over the next decade, improvements in cosmological parameter constraints will be driven by surveys of large-scale structure. Its inherent non-linearity suggests that significant information will be embedded in higher correlations beyond the…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-19 Joyce Byun , Alexander Eggemeier , Donough Regan , David Seery , Robert E. Smith

Complimenting recent work on the effective field theory of cosmological large scale structures, here we present detailed approximate analytical results and further pedagogical understanding of the method. We start from the collisionless…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-02 Mark P. Hertzberg

Modeling the nonlinearity of the halo bispectrum remains a major challenge in modern cosmology, in particular for ongoing and upcoming large-scale structure observations that are performed to study the inflationary physics. The "power…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-21 Chi-Ting Chiang

Primordial oscillatory features in the power spectrum of curvature perturbations are sensitive probes of the dynamics of the early Universe and can provide insights beyond the standard inflationary scenario. While these features have been…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-09 Mario Ballardini , Nicola Barbieri

We study the effect of nonperturbative corrections associated with the behavior of particles after shell crossing on the matter power spectrum. We compare their amplitude with the perturbative terms that can be obtained within the fluid…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Patrick Valageas

We present simple analytic approximations for the linear and fully evolved nonlinear mass power spectrum for spatially flat cold dark matter (CDM) cosmological models with quintessence (Q). Quintessence is a time evolving, spatially…

Astrophysics · Physics 2009-10-31 Chung-Pei Ma , R. R. Caldwell , Paul Bode , Limin Wang

The baryonic features in the galaxy power spectrum offer tight, time-resolved constraints on the expansion history of the Universe but complicate the measurement of the broadband shape of the power spectrum, which also contains precious…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-10 Katayoon Ghaemi , Nils Schöneberg , Licia Verde

We use a suite of high-resolution $N$-body simulations and state-of-the-art perturbation theory to improve the code halofit, which predicts the nonlinear matter power spectrum. We restrict attention to parameters in the vicinity of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-09 Robert E. Smith , Raul E. Angulo

Extracting the three dimensional power spectrum from the 2D distribution of galaxies has become a standard tool of cosmology. This extraction requires some assumptions about the scaling of the power spectrum with redshift; all treatments to…

Astrophysics · Physics 2007-05-23 R. Scranton , S. Dodelson

A cosmic shear survey, spanning a significant proportion of the sky, should greatly improve constraints on a number of cosmological parameters. It also provides a unique opportunity to examine the matter power spectrum directly. However,…

Astrophysics · Physics 2009-11-13 Fergus Simpson

Physical models for the hemispherical power asymmetry in the cosmic microwave background (CMB) reported by the Planck Collaboration must satisfy CMB constraints to the homogeneity of the Universe and quasar constraints to power asymmetries.…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-26 Liang Dai , Donghui Jeong , Marc Kamionkowski , Jens Chluba

The cosmological fluid equations describe the early gravitational dynamics of cold dark matter (CDM), exposed to a uniform component of dark energy, the cosmological constant $\Lambda$. Perturbative predictions for the fluid equations…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-26 Cornelius Rampf , Sonja Ornella Schobesberger , Oliver Hahn

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