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Related papers: Anisotropic expansion and SNIa: an open issue

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We confirm for the first time the existence of distinctive halo bias associated with the quadrupolar type of statistical anisotropy (SA) of the linear matter density field using cosmological $N$-body simulations. We find that the…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-19 Shogo Masaki , Maresuke Shiraishi , Takahiro Nishimichi , Teppei Okumura , Shuichiro Yokoyama

In this paper, we investigate the cosmic anisotropy from the SN-Q sample, consisting of the Pantheon sample and quasars, by employing the hemisphere comparison (HC) method and the dipole fitting (DF) method. Compared to the Pantheon sample,…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-18 J. P. Hu , Y. Y. Wang , F. Y. Wang

We review various cosmological models with a local underdense region (local void) and the averaged models with the backreaction of inhomogeneities, which have been proposed to explain (without assuming a positive cosmological constant) the…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-09 Kenji Tomita

(abridged) The signal-to-noise ratio (SNR) is used in gravitational-wave observations as the basic figure of merit for detection confidence and, together with the Fisher matrix, for the amount of physical information that can be extracted…

General Relativity and Quantum Cosmology · Physics 2015-03-20 Michele Vallisneri , Chad R. Galley

The assumption of homogeneity and isotropy on large scales is one of the main hypotheses of the standard cosmological model. In this paper, we revisit a test of cosmological isotropy using type Ia supernova (SN Ia) distances provided by the…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-01 Uendert Andrade , Carlos A. P. Bengaly , Beethoven Santos , Jailson S. Alcaniz

The dynamics of a homogeneous, anisotropic universe are investigated within the context of spinfoam cosmology. Transition amplitudes are calculated for a graph consisting of a single node and three links - the `Daisy graph' - probing the…

General Relativity and Quantum Cosmology · Physics 2013-11-21 Julian Rennert , David Sloan

We examine three SNe Type Ia datasets: Union2.1, JLA and Panstarrs to check their consistency using cosmology blind statistical analyses as well as cosmological parameter fitting. We find that Panstarrs dataset is the most stable of the…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-28 Ujjaini Alam , Jeremie Lasue

Radiation traversing the observable universe provides powerful ways to probe anisotropy of electromagnetic propagation. A controversial recent study claimed a signal of dipole character. Here we test a new and independent data set of 361…

Astrophysics · Physics 2011-09-16 Pankaj Jain , John P. Ralston

Most of current cosmological theories are built combining an isotropic and homogeneous manifold with a scale factor that depends on time. If one supposes a hyperconical universe with linear expansion, an inhomogeneous metric can be obtained…

General Relativity and Quantum Cosmology · Physics 2018-10-02 Robert Monjo

We discuss how Type Ia supernovae (SNe) strongly magnified by foreground galaxy clusters should be self-consistently treated when used in samples fitted for the cosmological parameters. While the cluster lens magnification of a SN can be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Adi Zitrin , Matthias Redlich , Tom Broadhurst

We present a novel method, based on a multiscale approach, for detecting anisotropy signatures in the arrival direction distribution of the highest energy cosmic rays. This method is catalog independent, i.e. it does not depend on the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 M. De Domenico , H. Lyberis

The single scattering theory is applied to spin noise spectroscopy (SNS). The case of two Gaussian probe beams tilted with respect to each other is analysed. It is shown that SNS signal in this case carry information about spatial…

Mesoscale and Nanoscale Physics · Physics 2016-11-08 G. G. Kozlov , V. S. Zapasskii , I. I. Ryzhov

We calculate the magnetic SANS cross section of dilute ensembles of uniformly magnetized and randomly-oriented Stoner-Wohlfarth particles using the Landau-Lifshitz equation. The focus of our study is on the angular anisotropy of the…

Materials Science · Physics 2022-10-18 Michael P. Adams , Evelyn Pratami-Sinaga , Andreas Michels

We investigate the sensitivity of the Laser Interferometer Space Antenna (LISA) to the anisotropies of the Stochastic Gravitational Wave Background (SGWB). We first discuss the main astrophysical and cosmological sources of SGWB which are…

We employ Maximum Likelihood Estimators to examine the Pantheon+ catalogue of Type Ia supernovae for large scale anisotropies in the expansion rate of the Universe. The analyses are carried out in the heliocentric frame, the CMB frame, as…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-02 Animesh Sah , Mohamed Rameez , Subir Sarkar , Christos Tsagas

The Laser Interferometer Space Antenna (LISA), a spaceborne gravitational wave (GW) detector set to launch in 2035, will observe several stochastic GW backgrounds in the mHz frequency band. At least one of these signals -- arising from the…

General Relativity and Quantum Cosmology · Physics 2024-12-24 Malachy Bloom , Alexander Criswell , Vuk Mandic

We present a cosmological analysis of the Lick Observatory Supernova Search (LOSS) Type Ia supernova (SN Ia) photometry sample introduced by Ganeshalingam et al. (2010). These SNe provide an effective anchor point to estimate cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-04 Mohan Ganeshalingam , Weidong Li , Alexei V. Filippenko

The arrival directions of ultra-high-energy cosmic rays appear to be approximately isotropically distributed over the whole sky, but the last-generation UHECR detector arrays, the Pierre Auger Observatory (Auger) and the Telescope Array…

We study characters of recent type Ia supernova (SNIa) data using evolving dark energy models with changing equation of state parameter w. We consider sudden-jump approximation of w for some chosen redshift spans with double transitions,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Jaehong Park , Chan-Gyung Park , Jai-chan Hwang

We examined the anisotropic point spread function (PSF) of Suprime-Cam data utilizing dense star field data. We decomposed the PSF ellipticities into three components, the optical aberration, atmospheric turbulence, and chip-misalignment in…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Takashi Hamana , Satoshi Miyazaki , Yuki Okura , Tomohiro Okamura , Toshifumi Futamase