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Related papers: Gauge Invariant Cosmological Perturbation Theory

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Some formulae for the perturbations of the matter fields are summarized within the framework of the second-order gauge-invariant cosmological perturbation theory in a four dimensional homogeneous isotropic universe, which is developed in…

General Relativity and Quantum Cosmology · Physics 2009-12-30 Kouji Nakamura

We present an approach to cosmological perturbations based on a covariant perturbative expansion between two worldlines in the real inhomogeneous universe. As an application, at an arbitrary order we define an exact scalar quantity which…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Kari Enqvist , Janne Hogdahl , Sami Nurmi , Filippo Vernizzi

The topic of this letter is structure formation with topological defects. We first present a partially new, fully local and gauge invariant system of perturbation equations to treat microwave background and dark matter fluctuations induced…

Astrophysics · Physics 2010-11-01 Ruth Durrer , Zhi-hong Zhou

This is the Part I paper of our series of full papers on a gauge-invariant {\it linear} perturbation theory on the Schwarzschild background spacetime which was briefly reported in our short papers [K.~Nakamura, Class. Quantum Grav. {\bf 38}…

General Relativity and Quantum Cosmology · Physics 2025-10-17 Kouji Nakamura

Inspired by the fully non-linear Geodesic Light-Cone (GLC) gauge, we consider its analogous set of coordinates which describes the unperturbed Universe. Given this starting point, we then build a cosmological perturbation theory on top of…

General Relativity and Quantum Cosmology · Physics 2021-02-15 Giuseppe Fanizza , Giovanni Marozzi , Matheus Medeiros , Gloria Schiaffino

Scalar perturbations of Friedmann-Lemaitre cosmologies can be analyzed in a variety of ways using Einstein's field equations, the Ricci and Bianchi identities, or the conservation equations for the stress-energy tensor, and possibly…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Claes Uggla , John Wainwright

Recently a new approach in constructing the conserved charges in cosmological Einstein's gravity was given. In this new formulation, instead of using the explicit form of the field equations a covariantly conserved rank four tensor was…

High Energy Physics - Theory · Physics 2019-05-07 Emel Altas

The second order perturbations in Friedmann-Robertson-Walker universe filled with a perfect fluid are completely formulated in the gauge invariant manner without any gauge fixing. All components of the Einstein equations are derived…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Kouji Nakamura

We use gauge-invariant cosmological perturbation theory to calculate the displacement field that sets the initial conditions for $N$-body simulations. Using first and second-order fully relativistic perturbation theory in the…

General Relativity and Quantum Cosmology · Physics 2016-03-02 Adam J. Christopherson , Juan Carlos Hidalgo , Cornelius Rampf , Karim A. Malik

We propose and construct a two-parameter perturbative expansion around a Friedmann-Lema\^{i}tre-Robertson-Walker geometry that can be used to model high-order gravitational effects in the presence of non-linear structure. This framework…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-15 Sophia R. Goldberg , Timothy Clifton , Karim A. Malik

Gauge-invariant treatments of the second-order cosmological perturbation in a four dimensional homogeneous isotropic universe are formulated without any gauge fixing. We have derived the Einstein equations in the case of the single perfect…

General Relativity and Quantum Cosmology · Physics 2009-01-27 Kouji Nakamura

We show that the perturbative expansion of general gauge theories can be expressed in terms of gauge invariant variables to all orders in perturbations. In this we generalize techniques developed in gauge invariant cosmological perturbation…

High Energy Physics - Theory · Physics 2023-01-11 Christoph Chiaffrino , Olaf Hohm , Allison F. Pinto

After introducing gauge-invariant cosmological perturbation theory we give an improved set of governing equations for multiple fluids including energy transfer. Having defined adiabatic and entropic perturbations we derive the…

Astrophysics · Physics 2007-05-23 Karim A. Malik

The second order perturbation calculations for gravity wave and Einstein equation for space time and matter are presented for the FRW metric cosmological model. While exact equations are found, suitable approximations are made to obtain…

High Energy Physics - Theory · Physics 2008-01-03 Ajay Patwardhan , Kartik Prabhu , M. S. R. Kumar

An attractive and simple hypothesis for the formation of large-scale structure is that it developed by gravitational instability from primordial fluctuations with an initially Gaussian probability distribution. Non-linear gravitational…

Astrophysics · Physics 2015-06-24 Ewa Luiza Lokas , Roman Juszkiewicz , David Weinberg , Francois Bouchet

We present a second-order gauge-invariant formalism to study the evolution of curvature perturbations in a Friedmann-Robertson-Walker universe filled by multiple interacting fluids. We apply such a general formalism to describe the…

Astrophysics · Physics 2009-11-10 N. Bartolo , S. Matarrese , A. Riotto

A brief introduction to the gauge invariant classical and quantum theory of cosmological perturbations is given. The formalism is applied to inflationary Universe models and yields a consistent and unified description of the generation and…

Astrophysics · Physics 2007-05-23 R. Brandenberger , H. Feldman , V. Mukhanov

We develop a perturbation theory for surfaces confining photons and massive particles in static spherically symmetric spacetimes in terms of two parameters: the mass-to-energy ratio and the deviation of metric functions from a given form,…

General Relativity and Quantum Cosmology · Physics 2024-10-22 Kirill Kobialko , Dmitri Gal'tsov

Along the general framework of the gauge-invariant perturbation theory developed in the papers [K. Nakamura, Prog. Theor. Phys. {\bf 110} (2003), 723; {\it ibid}, {\bf 113} (2005), 481.], we re-derive the second-order Einstein equations on…

General Relativity and Quantum Cosmology · Physics 2009-07-03 Kouji Nakamura

Cosmological perturbation theory is crucial for our understanding of the universe. The linear theory has been well understood for some time, however developing and applying the theory beyond linear order is currently at the forefront of…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-03 Adam J. Christopherson