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Related papers: Anisotropic separate universe simulations

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This article describes the theory of cosmological perturbations around a homogeneous and anisotropic universe of the Bianchi I type. Starting from a general parameterisation of the perturbed spacetime a la Bardeen, a complete set of gauge…

Astrophysics · Physics 2008-11-26 Thiago S. Pereira , Cyril Pitrou , Jean-Philippe Uzan

The non-zero mass of neutrinos suppresses the growth of cosmic structure on small scales. Since the level of suppression depends on the sum of the masses of the three active neutrino species, the evolution of large-scale structure is a…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-11 Jia Liu , Simeon Bird , José Manuel Zorrilla Matilla , J. Colin Hill , Zoltán Haiman , Mathew S. Madhavacheril , Andrea Petri , David N. Spergel

The global topology of the Universe can affect long-range gravitational forces via boundary conditions. Detailed studies of non-trivial topologies require simulations that natively adopt such geometries. Cosmological $N$-body simulations…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-13 Gábor Rácz , Viola H. Varga , Balázs Pál , István Szapudi , István Csabai , Till Sawala

We investigate non-linear scaling relations for two-dimensional gravitational collapse in an expanding background using a 2D TreePM code and study the strongly non-linear regime ($\bar\xi \leq 200$) for power law models. Evolution of these…

Astrophysics · Physics 2007-05-23 S. Ray , J. S. Bagla , T. Padmanabhan

Observational studies of galaxy isophotal shapes have shown that galaxy orientations are anisotropic: a galaxy's long axis tends to be oriented toward the center of its host. This radial alignment is seen across a wide range of scales, from…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-23 Maria J. Pereira , Greg L. Bryan

The standard cosmological model assumes a homogeneous and isotropic universe as the background spacetime on large scales called the cosmological principle. However, some observations suggest the possibility of an inhomogeneous and…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-08 Koki Yamashita , Yue Nan , Yuuki Sugiyama , Kazuhiro Yamamoto

We construct general anisotropic cosmological scenarios governed by an $f(R)=R^n$ gravitational sector. Focusing then on some specific geometries, and modelling the matter content as a perfect fluid, we perform a phase-space analysis. We…

General Relativity and Quantum Cosmology · Physics 2014-03-11 Genly Leon

The role of tidal shear in the formation of structure in the Universe is explored. To illustrate the possible and sometimes dramatic impact of tidal fields we focus on the evolution of voids. We firstly analyze the role of tidal fields both…

Astrophysics · Physics 2007-05-23 Rien van de Weygaert

Scale transformations have played an extremely successful role in studies of cosmological large-scale structure by relating the non-linear spectrum of cosmological density fluctuations to the linear primordial power at longer wavelengths.…

Astrophysics · Physics 2009-11-13 Jun Pan , Peter Coles , Istvan Szapudi

As a major source of cosmological information, galaxy clustering is susceptible to long-wavelength density and tidal fluctuations. These long modes modulate the growth and expansion rate of local structures, shifting them in both amplitude…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-28 Yin Li , Marcel Schmittfull , Uroš Seljak

Observations are inconsistent with a homogeneous and isotropic universe with ordinary matter and gravity. The universe is far from exact homogeneity and isotropy at late times, and the effect of the non-linear structures has to be…

Astrophysics · Physics 2012-05-01 Syksy Rasanen

Cosmological Perturbation Theory (PT) is a useful tool to study the cumulants of the density and velocity fields in the large scale structure of the Universe. In Papers I & II of this series we saw that the Spherical Collapse (SC) model…

Astrophysics · Physics 2009-10-30 P. Fosalba , E. Gaztanaga

After two decades of direct dynamical simulation of large-scale structure in the universe, it is safe to say the subject is now mature. Still, there are parts of the problem that are less well developed than others. In general, the…

Astrophysics · Physics 2007-05-23 August E. Evrard

We investigate cosmological evolution and implications of cosmic strings with time-dependent tension. We derive basic equations of time development of the correlation length and the velocity of such strings, based on the one scale model.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kazuhide Ichikawa , Tomo Takahashi , Masahide Yamaguchi

We discuss the effective field theory of large scale structure in terms of a single scalar degree of freedom, corresponding to the velocity potential of the matter fluid in a $\Lambda$CDM universe. This cosmic ``pion'' field is nonlinearly…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-15 Lara Celik , Bart Horn , Bhavya Mishra , David Muqattash

By means of the present geometrical and dynamical observational data, it is very hard to establish, from a statistical perspective, a clear preference among the vast majority of the proposed models for the dynamical dark energy and/or…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-07 Tomasz Denkiewicz , Vincenzo Salzano

The distribution of galaxies, halo abundance, and peculiar velocities are influenced by non-linear gravitational interactions, making the study of non-linear evolution crucial for accurate cosmological predictions. We explore these aspects…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-24 Swati Gavas

We report an experimental assessment of surface kinetic roughening properties that are anisotropic in space. Working for two specific instances of silicon surfaces irradiated by ion-beam sputtering under diverse conditions (with and without…

Materials Science · Physics 2015-06-11 Edoardo Vivo , Matteo Nicoli , Martin Engler , Thomas Michely , Luis Vázquez , Rodolfo Cuerno

Large-scale inhomogeneities and anisotropies are modeled using the Long Wavelength Iteration Scheme. In this scheme solutions are obtained as expansions in spatial gradients, which are taken to be small. It is shown that the choice of…

High Energy Physics - Theory · Physics 2007-05-23 G. L. Comer

We study the effect of a finite topology on the temperature correlations of the cosmic microwave background in a flat universe. Analytic expressions for the angular power spectrum are given for all possible finite flat models. We examine…

Astrophysics · Physics 2009-10-31 Evan Scannapieco , Janna Levin , Joseph Silk
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