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The multipole moments of the power spectrum of large scale structure, observed in redshift space, are calculated for a finite sample volume including the effects of both the linear velocity field and geometry. A variance calculation is also…

Astrophysics · Physics 2009-10-30 Andrew A. de Laix , Glenn Starkman

We test the possible dipole anisotropy of a Finslerian cosmological model and other three dipole-modulated cosmological models, i.e., the dipole-modulated $\rm{\Lambda}$CDM, $w$CDM and Chevallier--Polarski--Linder (CPL) model by using the…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-30 Zhe Chang , Dong Zhao , Yong Zhou

Large scale density modes are difficult to measure because they are sensitive to systematic observational errors in galaxy surveys, but we can study them indirectly by observing their impact on small scale perturbations. Cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2020-04-08 Peikai Li , Scott Dodelson , Rupert A. C. Croft

We analyze two volume limited galaxy samples from the SDSS photometric and spectroscopic data to test the isotropy in the local Universe. We use information entropy to quantify the global anisotropy in the galaxy distribution at different…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 Suman Sarkar , Biswajit Pandey , Rishi Khatri

The motion of our solar system relative to the CMB rest frame leads to subtle distortions in the observed CMB sky map due to the aberration effect. Usually the corresponding peculiar velocity is determined from the CMB dipole but neglecting…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-30 Ralf Aurich , David Reinhardt

The divergence of the momentum density field of the large scale structure generates a secondary anisotropy contribution to the Cosmic Microwave Background (CMB). While the effect is best described as a non-linear extension to the well-known…

Astrophysics · Physics 2009-11-13 Asantha Cooray , Naoki Seto

Strong gravitational lensing can be used to find otherwise invisible dark matter subhaloes. In such an analysis, the lens galaxy mass model is a significant source of systematic uncertainty. In this paper we analyse the effect of angular…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-15 Conor M. O'Riordan , Simona Vegetti

Spectra of density perturbations produced during chaotic inflation are calculated, taking both adiabatic and isocurvature modes into account in a class of scalar-tensor theories of gravity in which the dilaton is metrically coupled.…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Takeshi Chiba , Naoshi Sugiyama , Jun'ichi Yokoyama

We consider a general initial state for inflation as the mechanism for generating scale-dependent hemispherical asymmetry. An observable scale-dependent non-Gaussianity is generated that leads to observable hemispherical asymmetry from the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Hassan Firouzjahi , Jinn-Ouk Gong , Mohammad Hossein Namjoo

We study cosmological tensor perturbations induced by second-order scalar perturbations in the presence of anisotropic non-Gaussianity. This class of induced tensor modes arises on superhorizon scales through the intrinsic quadrupole…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-13 Atsuhisa Ota

We propose a data-driven approach to reconstruct the all-sky distribution of the dispersion measure contribution from the Galactic halo ($\mathrm{DM_{halo}}$) through a spherical harmonic expansion, enabling an investigation of its possible…

Astrophysics of Galaxies · Physics 2026-01-07 Yang Liu , Bao Wang , Puxun Wu , Jun-Jie Wei , Xue-Feng Wu

Motivated by the ~7 % dipole anisotropy in the distribution of ultra-high energy cosmic-rays (UHECRs) above 8 EeV, we explore the anisotropy induced by the large scale structure, using constrained simulations of the local Universe and…

High Energy Astrophysical Phenomena · Physics 2019-01-23 Noémie Globus , Tsvi Piran , Yehuda Hoffman , Edoardo Carlesi , Daniel Pomarède

We consider the imprints of local massive defects, such as a black hole or a massive monopole, during inflation. The massive defect breaks the background homogeneity. We consider the limit that the physical Schwarzschild radius of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-19 Hassan Firouzjahi , Asieh Karami , Tahereh Rostami

Using a generalized self-similar secondary infall model, which accounts for tidal torques acting on the halo, we analyze the velocity profiles of halos in order to gain intuition for N-body simulation results. We analytically calculate the…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-23 Phillip Zukin , Edmund Bertschinger

We investigate the dominant physical effects of superhorizon fluctuations in a flat FLRW universe, focusing on whether the combined evolution of scalar and tensor adiabatic modes in the near-horizon regime could lead to geometries beyond…

General Relativity and Quantum Cosmology · Physics 2025-04-02 Jorge Noreña , Thiago S. Pereira , Sean K. Reynolds

Our local motion with respect to the cosmic frame of rest is believed to be dominantly responsible for the observed dipole anisotropy in the Cosmic Microwave Background Radiation (CMBR). We study the effect of this motion on the sky…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-21 Gopal Kashyap , Naveen K. Singh , Khun Sang Phukon , Sarah Caudill , Pankaj Jain

We study a spherical, self-gravitating fluid model, which finds applications in cosmic structure formation. We argue that since the system features nonlinearity and gravity-induced dispersion, the emergence of solitons becomes possible. We…

Pattern Formation and Solitons · Physics 2024-02-21 G. N. Koutsokostas , S. Sypsas , O. Evnin , T. P. Horikis , D. J. Frantzeskakis

Our peculiar motion in a homogeneous and isotropic universe imprints a dipole in the cosmic microwave background (CMB) temperature field and similarly imprints a dipole in the distribution of extragalactic radio sources on the sky. Each of…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-05 Calum Murray

The apparent distribution of large-scale structures in the universe is sensitive to the velocity/potential of the sources as well as the potential along the line-of-sight through the mapping from real space to redshift space (redshift-space…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-04 Michel-Andrès Breton , Yann Rasera , Atsushi Taruya , Osmin Lacombe , Shohei Saga

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