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Perturbation theory of large-scale structures of the Universe at next-to-leading order and next-to-next-to-leading order provides us with predictions of cosmological statistics at sub-percent level in the mildly non-linear regime. Its use…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-08 Ken Osato , Takahiro Nishimichi , Atsushi Taruya , Francis Bernardeau

Inflationary cosmology provides a natural mechanism for the generation of primordial perturbations which seed the formation of observed cosmic structure and lead to specific signals of anisotropy in the cosmic microwave background…

Astrophysics · Physics 2011-07-19 Salman Habib , Andreas Heinen , Katrin Heitmann , Gerard Jungman

In the previous paper [arXiv:2210.10435], the nonlinear perturbation theory of cosmological density field is generalized to include the tensor-valued bias of astronomical objects, such as spins and shapes of galaxies and any other tensors…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-23 Takahiko Matsubara

Cosmic strings provide a radically different paradigm for the formation of structure to the prevailing inflationary one. They afford some extra technical complications: for example, the calculation of the power spectrum of matter and…

Astrophysics · Physics 2007-05-23 Mark Hindmarsh , Mairi Sakellariadou , Graham R. Vincent

In order to extract maximal information about cosmology from the large-scale structure of the Universe, one needs to use every bit of signal that can be observed. Beyond the spatial distributions of astronomical objects, the spatial…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-23 Takahiko Matsubara

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

Angular anisotropy techniques for cosmic diffuse radiation maps are powerful probes, even for quite small data sets. A popular observable is the angular power spectrum; we present a detailed study applicable to any unbinned source skymap…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Sheldon S. Campbell

The integrated perturbation theory (iPT) is a set of methods in nonlinear perturbation theory for the structure formation in the Universe. In Papers I and II [arXiv:2210.10435, arXiv:2210.11085], the basic formalism and technical methods of…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-23 Takahiko Matsubara

We study the accuracy with which cosmological parameters can be determined from real space power spectrum of matter density contrast at weakly nonlinear scales using analytical approaches. From power spectra measured in $N$-body simulations…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-03 Ken Osato , Takahiro Nishimichi , Francis Bernardeau , Atsushi Taruya

Angular power spectra are an important measure of the angular clustering of a given distribution. In Cosmology, they are applied to such vastly different observations as galaxy surveys that cover a fraction of the sky and the Cosmic…

Astrophysics · Physics 2007-11-15 Brett Hayes , Robert Brunner , Volodymyr Kindratenko

In almost all structure formation models, primordial perturbations are created within a homogeneous and isotropic universe, like the one we observe. Because their ensemble averages inherit the symmetries of the spacetime in which they are…

Astrophysics · Physics 2009-06-23 C. Armendariz-Picon

Recently a number of analytic prescriptions for computing the non-linear matter power spectrum have appeared in the literature. These typically involve resummation or closure prescriptions which do not have a rigorous error control, thus…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Jordan Carlson , Martin White , Nikhil Padmanabhan

We present the first calculation of the bispectrum of the matter perturbations induced by cosmic strings. The calculation is performed in two different ways: the first uses the unequal time correlators (UETCs) of the string network -…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Donough Regan , Mark Hindmarsh

Formulae are derived for the spectra of scalar curvature perturbations and gravitational waves produced during inflation, special cases of which include power law inflation, natural inflation in the small angle approximation and inflation…

General Relativity and Quantum Cosmology · Physics 2008-11-26 E. D. Stewart , D. H. Lyth

In Papers I-III [arXiv:2210.10435, arXiv:2210.11085, arXiv:2304.13304], we use the flat-sky and distant-observer approximations to develop a formalism with which the correlation statistics of cosmological tensor fields are calculated by the…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-23 Takahiko Matsubara

We present a simple numerical scheme for perturbation theory (PT) calculations of large-scale structure. Solving the evolution equations for perturbations numerically, we construct the PT kernels as building blocks of statistical…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-13 Atsushi Taruya

A large fraction of the information collected by cosmological surveys is simply discarded to avoid lengthscales which are difficult to model theoretically. We introduce a new technique which enables the extraction of useful information from…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-08 Fergus Simpson , J. Berian James , Alan F. Heavens , Catherine Heymans

Fluctuations in the large-scale structure of the Universe contain significant information about cosmological physics, but are modulated in survey datasets by various observational effects. Building on existing literature, we provide a…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-14 Chris Blake

The Large-Scale Structure (LSS) of the Universe provides valuable information for modern cosmology. The future redshift surveys, as DESI (Dark Energy Spectroscopic Instrument), will measure millions of galaxies and quasars, which allows to…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-27 Dante V. Gomez-Navarro

In performing cosmological N-body simulations, it is widely appreciated that the growth of structure on the largest scales within a simulation box will be inhibited by the finite size of the simulation volume. Following ideas set forth in…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-16 Chris Orban
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