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Measurements of the dark energy equation-of-state parameter, $w$, have been limited by uncertainty in the selection effects and photometric calibration of $z<0.1$ Type Ia supernovae (SNe Ia). The Foundation Supernova Survey is designed to…

Correctly interpreting observations of sources such as type Ia supernovae (SNe Ia) require knowledge of the power spectrum of matter on AU scales - which is very hard to model accurately. Because under-dense regions account for much of the…

宇宙学与河外天体物理 · 物理学 2013-11-22 V. C. Busti , R. F. L. Holanda , C. Clarkson

We combine the Ly-alpha forest power spectrum (LYA) from the Sloan Digital Sky Survey (SDSS) and high resolution spectra with cosmic microwave background (CMB) including 3-year WMAP, and supernovae (SN) and galaxy clustering constraints to…

天体物理学 · 物理学 2009-11-11 Uros Seljak , Anze Slosar , Patrick McDonald

The $\Lambda$CDM model is the current standard model in cosmology thanks to its ability to reproduce the observations. Its first observational evidence appeared from the type Ia supernovae (SNIa) Hubble diagram. However, there has been some…

宇宙学与河外天体物理 · 物理学 2019-05-01 Isaac Tutusaus , Brahim Lamine , Alain Blanchard

The energy density of a scalar field $\phi$ with potential $V(\phi) \propto \phi^{-\alpha}$, $\alpha > 0$, behaves like a time-variable cosmological constant that could contribute significantly to the present energy density. Predictions of…

天体物理学 · 物理学 2009-10-31 Silviu Podariu , Bharat Ratra

With the recent increase in precision of our cosmological datasets, measurements of $\Lambda$CDM model parameter provided by high- and low-redshift observations started to be in tension, i.e., the obtained values of such parameters were…

宇宙学与河外天体物理 · 物理学 2019-08-23 Matteo Martinelli , Isaac Tutusaus

Large scale astronomical surveys are going wider and deeper than ever before. However, astronomers, cosmologists and theorists continue to face the perennial issue that their data sets are often incomplete in magnitude space and must be…

宇宙学与河外天体物理 · 物理学 2018-04-10 M C March , R C Wolf , m Sako , C D'Andrea , D Brout

We examine the constraints that satellite-acquired Type Ia and IIP supernova apparent magnitude versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant…

天体物理学 · 物理学 2009-10-31 Silviu Podariu , Peter Nugent , Bharat Ratra

We show how Type Ia/II supernova rates at various redshifts can be used to follow the cosmic star formation rate (CSFR) history. Using the recent e stimate of the Cosmic Star Formation (CSFR), we compute the predicted cosmic Type Ia/II…

天体物理学 · 物理学 2016-08-30 R. Sadat

The universe with adiabatic matter creation is considered. It is thought that the negative pressure caused by matter creation can play the role of a dark energy component, and drive the accelerating expansion of the universe. Using the Type…

天体物理学 · 物理学 2015-06-24 Yuan Qiang , Tong-Jie Zhang , Ze-Long Yi

We present a systematic analysis of the cosmological constraints from the "Pantheon Sample" of 1048 Type Ia Supernovae (SNe Ia) in the redshift range $0.01<z<2.3$ compiled by Scolnic et al. (2018). Applying the flux-averaging method for…

宇宙学与河外天体物理 · 物理学 2019-07-10 Zhongxu Zhai , Yun Wang

The fitting of the observed redshifts and magnitudes of type Ia supernovae to what we would see in homogeneous cosmological models has led to constraints on cosmological parameters. However, in doing such fits it is assumed that the sampled…

天体物理学 · 物理学 2010-11-11 R. Ali Vanderveld

We investigate the validity of the Cosmological Principle by mapping the cosmological parameters $H_0$ and $q_0$ through the celestial sphere. In our analysis, performed in a low-redshift regime to follow a model-independent approach, we…

宇宙学与河外天体物理 · 物理学 2015-07-21 C. A. P. Bengaly , A. Bernui , J. S. Alcaniz

The observation of Type Ia supernovae (SNe Ia) plays an essential role in probing the expansion history of the universe. But the possible presence of cosmic opacity can degrade the quality of SNe Ia. The gravitational-wave (GW) standard…

宇宙学与河外天体物理 · 物理学 2019-05-15 Jun-Jie Wei

Tiny systematic uncertainty caused by cosmological hypotheses is hard to be detected, not only because the present observational errors are relatively large but also because hypothesis-induced uncertainty is indistinguishable from other…

宇宙学与河外天体物理 · 物理学 2015-08-20 Jiaxin Wang , Xinhe Meng

Model-independent estimations for the spatial curvature not only provide a test for the fundamental Copernican principle assumption, but also can effectively break the degeneracy between curvature and dark energy properties. In this paper,…

宇宙学与河外天体物理 · 物理学 2016-12-28 Zhengxiang Li , Guo-Jian Wang , Kai Liao , Zong-Hong Zhu

Observations of type Ia supernovae include information about the characteristic nucleosynthesis associated with these thermonuclear explosions. We consider observational constraints from iron-group elemental and isotopic ratios, to compare…

We present cosmological constraints from a cosmic shear analysis of the fourth data release of the Kilo-Degree Survey (KiDS-1000), doubling the survey area with nine-band optical and near-infrared photometry with respect to previous KiDS…

A multipole expansion analysis is applied to 1420 MHz radio continuum images of supernova remnants (SNRs) in order to compare Type Ia and core collapse (CC) SNRs. Because the radio synchrotron emission is produced at the outer shock between…

高能天体物理现象 · 物理学 2019-09-27 Sujith Ranasinghe , Denis Leahy

The Ultraviolet Near Infrared Optical Northern Survey (UNIONS) is a photometric survey in the northern sky. The quality of the data in the $r$ band provides precise shape measurements to measure the growth of structures using cosmic shear.…