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The large scale distribution of galaxies in the universe displays a complex pattern of clusters, super-clusters, filaments and voids with sizes limited only by the boundaries of the available samples. A quantitative statistical…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Francesco Sylos Labini , Luciano Pietronero

The spatial curvature of the universe is not yet known. Even though at present the Universe is very close to being essentially flat and most signatures of curvature appear to have been diluted by inflation, if the number of e-foldings…

High Energy Physics - Theory · Physics 2021-12-23 Sebastian Cespedes , Senarath de Alwis , Francesco Muia , Fernando Quevedo

Previously defined covariant and gauge-invariant perturbation variables, representing, e.g., the fractional spatial energy density gradient on hypersurfaces of constant expansion, are used to simplify the linear perturbation analysis of a…

Astrophysics · Physics 2009-10-30 Winfried Zimdahl

Prompted by the recent more precise determination of the basic cosmological parameters and growing evidence that the matter-energy content of the universe is now dominated by dark energy and dark matter we present the general solution of…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Marek Demianski , Zdzislaw A. Golda , Andrzej Woszczyna

In inflation cosmologies, cosmic structure develops through the gravitational instability of the inevitable quantum noise in primordial scalar fields. I show how the acceleration of the universe defines the shape of the primordial spectrum…

Astrophysics · Physics 2009-09-25 J. Richard Bond

A brief account is given of large-scale structure modelling based on the assumption that the initial perturbations arise from inflation. A recap is made of the implications of inflation for large-scale structure; under the widely applicable…

Astrophysics · Physics 2007-05-23 Andrew R Liddle

We consider scalar perturbations of energy-density for a class of cosmological models where an early phase of accelerated expansion evolves, without any fine-tuning for graceful exit, towards the standard Friedman eras of observed universe.…

General Relativity and Quantum Cosmology · Physics 2011-05-10 S. Capozziello , G. Lambiase , G. Scarpetta

We perform large-scale cosmological simulations that solve Einstein's equations directly via numerical relativity. Starting with initial conditions sampled from the cosmic microwave background, we track the emergence of a cosmic web without…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-27 Hayley J. Macpherson , Daniel J. Price , Paul D. Lasky

The effect of capture of a cosmic object by the central gravitational field of a galaxy cluster is described in the expanding Universe. The cosmic evolution can be the origin of the capture explaining formation of galaxies and their…

Astrophysics · Physics 2007-06-07 Piotr Flin , Victor Pervushin , Andrey Zorin

Massive particles leave imprints on primordial non-Gaussianity via couplings to the inflaton, even despite their exponential dilution during inflation: practically, the Universe acts as a Cosmological Collider. We present the first…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-14 Giovanni Cabass , Oliver H. E. Philcox , Mikhail M. Ivanov , Kazuyuki Akitsu , Shi-Fan Chen , Marko Simonović , Matias Zaldarriaga

Cosmological inflation generates a spectrum of density perturbations that can seed the cosmic structures we observe today. These perturbations are usually computed as the result of the gravitationally-induced spontaneous creation of…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-12 Ivan Agullo , Leonard Parker

Spectrum of density perturbations in the Universe generated from quantum-gravitational fluctuations in slow-roll-over inflationary scenarios with the Brans-Dicke gravity is calculated. It is shown that after inflation the isocurvature mode…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Alexei A. Starobinsky , Jun'ichi Yokoyama

A mildly inhomogeneous universe with a cosmological constant may look like it contains evolving dark energy. We show that could be the case by modelling the inhomogeneities and their effects in three different ways: as clumped matter…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-29 Yonadav Barry Ginat , Pedro G. Ferreira

We solve one of the open problems in Einstein-Cartan theory, namely we find a natural matter source whose spin angular momentum tensor is compatible with the cosmological principle. We analyze the resulting evolution equations and find that…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Christian G. Boehmer , James Burnett

We study primordial perturbations generated from quantum fluctuations of an inflaton based on the formalism of stochastic gravity. Integrating out the degree of freedom of the inflaton field, we analyze the time evolution of the correlation…

High Energy Physics - Theory · Physics 2008-11-26 Yuko Urakawa , Kei-ichi Maeda

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

Cosmic growth of large scale structure probes the entire history of cosmic expansion and gravitational coupling. To get a clear picture of the effects of modification of gravity we consider a deviation in the coupling strength (effective…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-19 Mikhail Denissenya , Eric V. Linder

Focus of these lectures is the challenge of explaining the origin of structure in the Universe. The interplay between quantum field theory and classical general relativity has given rise to several interesting cosmological models which…

Astrophysics · Physics 2007-05-23 O. Eboli , V. Ribelles

Torsion effects, including a spin precession in the torsion field, are considered. Some properties of neutrinos in cosmology are discussed. In the framework of Trautman's cosmological model with torsion estimated is a specific angular…

Astrophysics · Physics 2009-10-31 M. L. Fil'chenkov

In the present work we discuss inflation, dark matter and cosmological evolution in the context of the brane-world scenario. Being string theory inspired, the brane-world models provide corrections to the General Relativity, which is…

High Energy Physics - Phenomenology · Physics 2012-05-28 G. Panotopoulos