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Related papers: Cosmological Perturbation Theory Using the FFTLog:…

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Effective field theory provides a perturbative framework to study the evolution of cosmological large-scale structure. We investigate the underpinnings of this approach, and suggest new ways to compute correlation functions of cosmological…

High Energy Physics - Theory · Physics 2014-07-16 Sean M. Carroll , Stefan Leichenauer , Jason Pollack

We introduce an Eulerian Perturbation Theory to study the clustering of tracers for cosmologies in the presence of massive neutrinos. Our approach is based on mapping recently-obtained Lagrangian Perturbation Theory results to the Eulerian…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-12 Alejandro Aviles , Arka Banerjee , Gustavo Niz , Zachary Slepian

We present a fast implementation of the next-to-leading order (1-loop) redshift-space galaxy power spectrum by using FFTlog-based methods. [V. Desjacques, D. Jeong, and F. Schmidt, JCAP 1812 (12), 035] have shown that the 1-loop galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-27 Joseph Tomlinson , Henry S. Grasshorn Gebhardt , Donghui Jeong

Angular statistics of cosmological observables are hard to compute. The main difficulty is due to the presence of highly-oscillatory Bessel functions which need to be integrated over. In this paper, we provide a simple and fast method to…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-12 Valentin Assassi , Marko Simonović , Matias Zaldarriaga

Inhomogeneous cosmological perturbation equations are derived in loop quantum gravity, taking into account corrections in particular in gravitational parts. This provides a framework for calculating the evolution of modes in structure…

We compute the two-loop effective field theory (EFT) power spectrum of dark matter density fluctuations in $\Lambda$CDM using the recently proposed COBRA method (Bakx. et al, 2025). With COBRA, we are able to evaluate the two-loop matter…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-11 Thomas Bakx , Henrique Rubira , Nora Elisa Chisari , Zvonimir Vlah

We construct a position-space cosmological perturbation theory around spatially flat Friedmann-Lema\^itre-Robertson-Walker geometries that allows to model localized primordial sources of gravitational waves. The equations of motion are…

General Relativity and Quantum Cosmology · Physics 2026-04-13 Geoffrey Compère , Sk Jahanur Hoque

The path-integral approach to cosmology consists in the computation of transition amplitudes between states of the quantum geometry of the universe. In the past, the concrete computation of these transitions amplitudes has been performed in…

General Relativity and Quantum Cosmology · Physics 2012-05-22 Francesca Vidotto

Aspects of the full theory of loop quantum gravity can be studied in a simpler context by reducing to symmetric models like cosmological ones. This leads to several applications where loop effects play a significant role when one is…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Martin Bojowald

The matter density field exhibits a nearly lognormal probability density distribution (PDF) after entering into the nonlinear regime. Recently, it has been shown that the shape of the power spectrum of a logarithmically transformed density…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Xin Wang , Mark Neyrinck , István Szapudi , Alex Szalay , Xuelei Chen , Julien Lesgourgues , Antonio Riotto , Martin Sloth

We derive an effective field theory (EFT) for cosmological Lyman alpha forest fluctuations valid for the power spectrum at the one-loop order. The ``bottom-up'' EFT expansion at the level of the transmitted flux is identical to the…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-04 Mikhail M. Ivanov

We apply the full theory of Loop Quantum Gravity (LQG) to cosmology and present a top-down derivation of gauge-invariant cosmological perturbation theory from quantum gravity. The derivation employs the reduced phase space formulation of…

General Relativity and Quantum Cosmology · Physics 2021-01-20 Muxin Han , Haida Li , Hongguang Liu

The next generation of cosmological surveys will operate over unprecedented scales, and will therefore provide exciting new opportunities for testing general relativity. The standard method for modelling the structures that these surveys…

General Relativity and Quantum Cosmology · Physics 2018-03-28 Sophia R. Goldberg , Christopher Gallagher , Timothy Clifton

The correlators of large-scale fluctuations belong to the most important observables in modern cosmology. Recently, there have been considerable efforts in analytically understanding the cosmological correlators and the related wavefunction…

High Energy Physics - Theory · Physics 2024-03-14 Bingchu Fan , Zhong-Zhi Xianyu

While homogeneous cosmologies have long been studied in the group field theory (GFT) approach to quantum gravity, including a quantum description of cosmological perturbations is highly non-trivial. Here we apply a recent proposal for…

General Relativity and Quantum Cosmology · Physics 2025-11-18 Steffen Gielen , Lisa Mickel

In the context of high-energy particle physics, a reliable theory-experiment confrontation requires precise theoretical predictions. This translates into accessing higher-perturbative orders, and when we pursue this objective, we inevitably…

High Energy Physics - Phenomenology · Physics 2024-09-12 German Sborlini

I present a streamlined review of how the separate universe approach to cosmological perturbation theory can be used to study the dynamics of long-wavelength scalar perturbations in loop quantum cosmology, and then use it to calculate how…

General Relativity and Quantum Cosmology · Physics 2016-08-03 Edward Wilson-Ewing

A brief review of various numerical techniques used in loop quantum cosmology and results is presented. These include the way extensive numerical simulations shed insights on the resolution of classical singularities, resulting in the key…

General Relativity and Quantum Cosmology · Physics 2013-07-11 Parampreet Singh

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

Nonlinear effects are crucial in order to compute the cosmological matter power spectrum to the accuracy required by future generation surveys. Here, a new approach is presented, in which the power spectrum, the bispectrum and higher order…

Astrophysics · Physics 2009-11-13 Massimo Pietroni