English
Related papers

Related papers: Non-linear perturbation theory extension of the Bo…

200 papers

In the previous paper [arXiv:2210.10435], the nonlinear perturbation theory of cosmological density field is generalized to include the tensor-valued bias of astronomical objects, such as spins and shapes of galaxies and any other tensors…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-23 Takahiko Matsubara

We consider nonlinear redshift-dependent equation of state parameters as dark energy models in a spatially flat Friedmann-Lema\^itre-Robertson-Walker universe. To depict the expansion history of the universe in such cosmological scenarios,…

General Relativity and Quantum Cosmology · Physics 2018-02-06 Weiqiang Yang , Supriya Pan , Andronikos Paliathanasis

We develop the transport operator formalism, a new line-of-sight integration framework to calculate the anisotropies of the Cosmic Microwave Background (CMB) at the linear and non-linear level. This formalism utilises a transformation…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-25 Christian Fidler , Kazuya Koyama , Guido W. Pettinari

Nonlinear electrical response permits a unique window into effects of band structure geometry. It can be calculated either starting from a Boltzmann approach for small frequencies, or using Kubo's formula for resonances at finite frequency.…

Mesoscale and Nanoscale Physics · Physics 2023-04-26 Daniel Kaplan , Tobias Holder , Binghai Yan

The galaxy power spectrum is now a well-known tool of precision cosmology. In addition to the overall shape, baryon oscillations and the small-scale suppression of power by massive neutrinos capture complimentary information on cosmological…

Astrophysics · Physics 2009-11-10 Asantha Cooray

We present a method for suppressing contributions from higher-order terms in perturbation theory, greatly increasing the amount of information which may be extracted from the matter power spectrum. In an evolved cosmological density field…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Fergus Simpson , Alan F. Heavens , Catherine Heymans

We present a new flexible, fast and accurate way to implement massive neutrinos, warm dark matter and any other non-cold dark matter relics in Boltzmann codes. For whatever analytical or numerical form of the phase-space distribution…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-14 Julien Lesgourgues , Thomas Tram

We develop a new approach to study the nonlinear evolution in the large-scale structure of the Universe both in real space and in redshift space, extending the standard perturbation theory of gravitational instability. Infinite series of…

Astrophysics · Physics 2008-11-26 Takahiko Matsubara

Cosmological Boltzmann codes are often used by researchers for calculating the CMB angular power spectra from different theoretical models, for cosmological parameter estimation, etc. Therefore, the accuracy of a Boltzmann code is of utmost…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-09 Santanu Das , Anh Phan

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 present the leading order non-linear density and velocity power spectra in the complete form; previous studies have omitted the vector- and tensor-type perturbations simultaneously excited by the scalar-type perturbation in nonlinear…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-22 Jai-chan Hwang , Donghui Jeong , Hyerim Noh

We explore the Lagrangian perturbation theory (LPT) at 1-loop order with Gaussian initial conditions. We present an expansion method to approximately compute the power spectrum in LPT. Our approximate solution has good convergence in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 Naonori S. Sugiyama

We describe the implementation of a new approach to the numerical evaluation of the effects of non-cold relics on the evolution of cosmological perturbations. The Boltzmann hierarchies used to compute the contributions of these relics to…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-03 Nanoom Lee , José Luis Bernal , Sven Günther , Lingyuan Ji , Marc Kamionkowski

The perturbative approach to structure formation has recently received a lot of attention in the literature. In such setups the final predictions for observables like the power spectrum is often derived under additional approximations such…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Matteo Fasiello , Zvonimir Vlah

This work investigates the nonlinearity of the power-law model of F(T) gravity, highlighting the inability of the Boltzmann solver CLASS to handle nonlinear models. As a workaround, a second-order Taylor expansion is applied to the…

General Relativity and Quantum Cosmology · Physics 2025-12-23 Robert Rugg , Shambel Akalu , Amare Abebe

We estimate the velocity field in a large set of $N$-body simulations including massive neutrino particles, and measure the auto-power spectrum of the velocity divergence field as well as the cross-power spectrum between the cold dark…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-13 Julien Bel , Andrea Pezzotta , Carmelita Carbone , Emiliano Sefusatti , Luigi Guzzo

We present cosmological parameter measurements from the publicly available Baryon Oscillation Spectroscopic Survey (BOSS) data on anisotropic galaxy clustering in Fourier space. Compared to previous studies, our analysis has two main novel…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-28 Mikhail M. Ivanov , Marko Simonović , Matias Zaldarriaga

The 3D matter power spectrum, $P_{\delta}(k,z)$ is a fundamental quantity in the analysis of cosmological data such as large-scale structure, 21cm observations, and weak lensing. Existing computer models (Boltzmann codes) such as CLASS can…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-09 Arrykrishna Mootoovaloo , Andrew H. Jaffe , Alan F. Heavens , Florent Leclercq

We present the public version of hi_class (www.hiclass-code.net), an extension of the Boltzmann code CLASS to a broad ensemble of modifications to general relativity. In particular, hi_class can calculate predictions for models based on…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-17 Miguel Zumalacarregui , Emilio Bellini , Ignacy Sawicki , Julien Lesgourgues , Pedro G. Ferreira

We develop an effective theory for biased tracers formulated at the level of the Boltzmann equation, providing a unified description of density and velocity bias. We introduce a general effective collision term in the tracer Boltzmann…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-01 Tomohiro Fujita , Tomo Takahashi , Sora Yamashita