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Related papers: Loop Corrections in Non-Linear Cosmological Pertur…

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In this paper we investigate the scalar mode of first-order metric perturbations over spatially flat FRW spacetime when the holonomy correction is taken into account in the semi-classical framework of loop quantum cosmology. By means of the…

High Energy Physics - Theory · Physics 2010-05-28 Jian-Pin Wu , Yi Ling

A fully consistent linear perturbation theory for cosmology is derived in the presence of quantum corrections as they are suggested by properties of inverse volume operators in loop quantum gravity. The underlying constraints present a…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Golam Mortuza Hossain , Mikhail Kagan , S. Shankaranarayanan

I attempt to analyse the next-to-leading-order non-holomorphic contribution to the Wilsonian low-energy effective action in the four-dimensional N=2 gauge theories with matter, from the manifestly N=2 supersymmeric point of view, by using…

High Energy Physics - Theory · Physics 2016-08-25 Sergei V. Ketov

A large fraction of cosmological information on dark energy and gravity is encoded in the nonlinear regime. Precision cosmology thus requires precision modeling of nonlinearities in general dark energy and modified gravity models. We modify…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Weiguang Cui , Pengjie Zhang , Xiaohu Yang

We calculate one--loop corrections to the vertexes and propagators of photons and charged particles in the strong electric field backgrounds. We use the Schwinger--Keldysh diagrammatic technique. We observe that photon's Keldysh propagator…

High Energy Physics - Theory · Physics 2015-06-19 E. T. Akhmedov , N. Astrakhantsev , F. K. Popov

In this paper we calculate the linear perturbations of the cosmological redshift drift. We show explicitly that our expressions are gauge-invariant and compute the power spectrum of the redshift drift perturbations and its correlations with…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-30 Pedro Bessa , Ruth Durrer , Dennis Stock

We study the third order solutions of the cosmological density perturbations in the Horndeski's most general scalar-tensor theory under the condition that the Vainshtein mechanism is at work. In this work, we thoroughly investigate the…

General Relativity and Quantum Cosmology · Physics 2015-11-25 Yuichiro Takushima , Ayumu Terukina , Kazuhiro Yamamoto

Large scale structure surveys are likely the next leading probe of cosmological information. It is therefore crucial to reliably predict their observables. The Effective Field Theory of Large Scale Structures (EFTofLSS) provides a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 John Joseph M. Carrasco , Simon Foreman , Daniel Green , Leonardo Senatore

We compute the one-loop quantum corrections to the gravitational potentials of a spinning point particle in a de Sitter background, due to the vacuum polarisation induced by conformal fields in an effective field theory approach. We…

High Energy Physics - Theory · Physics 2017-04-19 Markus B. Fröb , Enric Verdaguer

We present a new method for calculating loops in cosmological perturbation theory. This method is based on approximating a $\Lambda$CDM-like cosmology as a finite sum of complex power-law universes. The decomposition is naturally achieved…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-25 Marko Simonović , Tobias Baldauf , Matias Zaldarriaga , John Joseph Carrasco , Juna A. Kollmeier

We disclose the effects of the entropic corrections to the Friedmann equations on the growth of perturbations in the early stages of the universe. We consider two types of corrections to the area law of entropy, known as Tsallis and Barrow…

General Relativity and Quantum Cosmology · Physics 2022-12-12 Bita Farsi , Ahmad Sheykhi

We study the gravitational correction to the gauge couplings in the extra dimension model where the gravity propagates in the (4+n)-dimensional bulk. We show by explicit calculation in the background field method that the one-loop…

High Energy Physics - Phenomenology · Physics 2008-09-12 Feng Wu , Ming Zhong

We consider two different definitions for loop corrections to the primordial power spectra. One of these is to simply correct the mode functions in the tree order relations using the linearized effective field equations. The second…

High Energy Physics - Theory · Physics 2015-06-16 S. P. Miao , Sohyun Park

We explore the consequences of loop quantum cosmology (inverse-volume corrections) in the spectrum of the gravitational waves using the method of the Bogoliubov coefficients. These corrections are taken into account at the background level…

General Relativity and Quantum Cosmology · Physics 2014-01-22 Joao Morais , Mariam Bouhmadi-Lopez , Alfredo B. Henriques

Cosmological perturbation theory is a powerful tool to predict the statistics of large-scale structure in the weakly non-linear regime, but even at 1-loop order it results in computationally expensive mode-coupling integrals. Here we…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-17 Xiao Fang , Jonathan A. Blazek , Joseph E. McEwen , Christopher M. Hirata

We study the general relativistic non-linear dynamics of self-gravitating irrotational dust in a cosmological setting, adopting the comoving and synchronous gauge, where all the equations can be written in terms of the metric tensor of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Eleonora Villa , Sabino Matarrese , Davide Maino

We present a fully covariant and gauge-invariant analysis of linear cosmological perturbations in Energy-Momentum Squared Gravity. Working within the 1+3 formalism, we derive the exact propagation equations for scalar, vector, and tensor…

General Relativity and Quantum Cosmology · Physics 2025-11-10 Peter K. S. Dunsby , Maria-Alexia Caldis , Eduardo Bittencourt

We describe various expansion schemes that can be used to study gravitational clustering. Obtained from the equations of motion or their path-integral formulation, they provide several perturbative expansions that are organized in different…

Astrophysics · Physics 2009-11-13 P. Valageas

We investigate the accuracy of Eulerian perturbation theory for describing the matter and galaxy power spectra in real and redshift space in light of future observational probes for precision cosmology. Comparing the analytical results with…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-05 Héctor Gil-Marín , Christian Wagner , Licia Verde , Cristiano Porciani , Raul Jimenez

We analyze the SDSS Ly-alpha forest P_F(k,z) measurement to determine the linear theory power spectrum. Our analysis is based on fully hydrodynamic simulations, extended using hydro-PM simulations. We account for the effect of absorbers…