Uncorrelated measurements of the cosmic expansion history and dark energy from supernovae

2005 ◽  
Vol 71 (10) ◽  
Author(s):  
Yun Wang ◽  
Max Tegmark
Keyword(s):  
Dark Energy ◽  
Cosmic Expansion ◽  
Cosmic Expansion History

scholarly journals The WiggleZ Dark Energy Survey: measuring the cosmic expansion history using the Alcock-Paczynski test and distant supernovae

2011 ◽  
Vol 418 (3) ◽  
pp. 1725-1735 ◽  
Author(s):  
Chris Blake ◽  
Karl Glazebrook ◽  
Tamara M. Davis ◽  
Sarah Brough ◽  
Matthew Colless ◽  
...  
Keyword(s):  
Dark Energy ◽  
Cosmic Expansion ◽  
Dark Energy Survey ◽  
Energy Survey ◽  
Cosmic Expansion History

scholarly journals The Joint Efficient Dark-energy Investigation (JEDI): measuring the cosmic expansion history from type Ia supernovae

2006 ◽  
Author(s):  
M. M. Phillips ◽  
Peter Garnavich ◽  
Yun Wang ◽  
David Branch ◽  
Edward Baron ◽  
...  
Keyword(s):  
Dark Energy ◽  
Type Ia Supernovae ◽  
Cosmic Expansion ◽  
Type Ia ◽  
Ia Supernovae ◽  
Cosmic Expansion History

scholarly journals Finding possibility of dynamical dark energy with Hubble parameters

2014 ◽  
Vol 29 (32) ◽  
pp. 1450155 ◽  
Author(s):  
Jiaxin Wang ◽  
Xinhe Meng
Keyword(s):  
Dark Energy ◽  
Null Hypothesis ◽  
High Redshift ◽  
Hubble Constant ◽  
Cosmic Expansion ◽  
Diagnostic Approaches ◽  
Hubble Parameters ◽  
Dynamical Dark Energy ◽  
Cosmic Expansion History ◽  
Constant Dark

The Hubble parameter is a critical measurement in cosmology, which contains the most direct information of the cosmic expansion history. Since discrepancy is found between low redshift and high redshift estimations of Hubble constant, we are interested in whether that tension indicates dynamical dark energy. In this paper, we emphasize that the observed Hubble parameters at various redshifts, along with observed Hubble constant, can help us in probing the evolutional behavior of the mysterious dark energy. Null hypothesis tests are carried out with two diagnostic approaches. We find out that, according to the present measurements of Hubble parameters, rejection of constant dark energy is captured at 1σ level from null tests with and without the observed value of Hubble constant.

THE EFFECT OF CURVATURE IN DETERMINING THE PROPERTY OF DARK ENERGY FROM TYPE IA SUPERNOVA WITH A MODEL INDEPENDENT METHOD

2013 ◽  
Vol 22 (06) ◽  
pp. 1350025 ◽  
Author(s):  
XIANGYUN FU ◽  
PUXUN WU ◽  
HONGWEI YU ◽  
BINGJU ZHOU
Keyword(s):  
Dark Energy ◽  
Smoothing Function ◽  
Spatial Curvature ◽  
Apparent Effect ◽  
Cosmic Expansion ◽  
Type Ia ◽  
Model Independent ◽  
Ia Supernovae ◽  
Energy Property ◽  
Cosmic Expansion History

The effect of spatial curvature in reconstructing the cosmic expansion history and the property of dark energy is studied in this paper by smoothing the noise of the Union2.1 Type Ia Supernovae (SNIa) data with a Gaussian smoothing function. We find that the spatial curvature induces an apparent effect in reconstructing the Hubble parameter H(z), the deceleration parameter q(z), and especially on the equation of state w(z) of dark energy. Thus, when one probes the dark energy property, an assumption of a flat universe may induce critical bias and it is imperative to take account of the spatial curvature.

Ghost dark energy in Rastall theory

2021 ◽  
pp. 2150090
Author(s):  
E. E. Kangal ◽  
M. Salti ◽  
O. Aydogdu
Keyword(s):  
Dark Energy ◽  
Energy Density ◽  
Text Analysis ◽  
Functional Form ◽  
Expansion Rate ◽  
Dark Energy Density ◽  
Cosmic Expansion ◽  
Astrophysical Data ◽  
Ghost Dark Energy ◽  
History Of

Making use of the generalized form of the Ghost dark energy density, which has the functional form [Formula: see text] where [Formula: see text] represents the Hubble expanding rate, the present accelerated enlargement behavior of the cosmos is investigated from the Rastall theory perspective. After finding a relation for the Hubble cosmic expansion rate, we consider recent cosmology-independent measurements calculated for the expansion history of the cosmos to fit the model via the [Formula: see text]-analysis. Moreover, we discuss the cosmographic properties of the model with the help of some cosmological quantities. We show that our model is stable and consistent with the recent astrophysical data. Also, for our model, we investigate cosmological interpretations of thermodynamics.

scholarly journals Cosmic Expansion History from Line-Intensity Mapping

2019 ◽  
Vol 123 (25) ◽  
Author(s):  
José Luis Bernal ◽  
Patrick C. Breysse ◽  
Ely D. Kovetz
Keyword(s):  
Line Intensity ◽  
Cosmic Expansion ◽  
Intensity Mapping ◽  
Cosmic Expansion History

PALATINI f(R) COSMOLOGY

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1388-1396 ◽  
Author(s):  
SEOKCHEON LEE
Keyword(s):  
Linear Growth ◽  
Matter Density ◽  
Modified Theories Of Gravity ◽  
Cosmic Expansion ◽  
Energy Models ◽  
Modified Gravity Theories ◽  
Theories Of Gravity ◽  
The Stability ◽  
Cosmic Expansion History ◽  
General Gauge

We investigate the modified gravity theories in terms of the effective dark energy models. We compare the cosmic expansion history and the linear growth in different models. We also study the evolution of linear cosmological perturbations in modified theories of gravity assuming the Palatini formalism. We find the stability of the superhorizon metric evolution depends on models. We also study the matter density fluctuation in the general gauge and show the differential equations in super and sub-horizon scales.

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