scholarly journals A search for the variation of speed of light using galaxy cluster gas mass fraction measurements

2021 ◽  
Vol 2021 (11) ◽  
pp. 034
Author(s):  
I.E.C.R. Mendonça ◽  
Kamal Bora ◽  
R.F.L. Holanda ◽  
Shantanu Desai ◽  
S.H. Pereira
Keyword(s):  
Mass Fraction ◽  
Galaxy Cluster ◽  
New Method ◽  
Type Ia Supernovae ◽  
Speed Of Light ◽  
Type Ia ◽  
Ia Supernovae

Abstract In this paper, we implement a new method to test the invariance of the speed of light (c) as a function of redshift, by combining the measurements of galaxy cluster gas mass fraction, H(z) from cosmic chronometers, and Type-Ia supernovae (SNe Ia). In our analyses, we consider both a constant depletion factor (which corresponds to the ratio by which the cluster gas mass fraction is depleted with respect to the universal baryonic mean) and one varying with redshift. We also consider the influence of different H 0 estimates on our results. We look for a variation of c, given by c(z) = c 0(1+c 1 z). We find a degeneracy between our final results on c variation and the assumptions on the gas mass fraction depletion factor. Most of our analyses indicate negligible variation of the speed of light.

scholarly journals CONSTRAINTS ON THE COSMOLOGICAL DENSITY PARAMETERS AND COSMIC TOPOLOGY

2007 ◽  
Vol 16 (02n03) ◽  
pp. 207-217 ◽  
Author(s):  
M. J. REBOUÇAS
Keyword(s):  
Mass Fraction ◽  
Type Ia Supernovae ◽  
Data Sets ◽  
X Ray ◽  
Set Constraints ◽  
Type Ia ◽  
Ia Supernovae ◽  
The Universe ◽  
Nontrivial Topology ◽  
Spatial Section

A nontrivial topology of the spatial section of the universe is an observable which can be probed for all homogeneous and isotropic universes, without any assumption on the cosmological density parameters. We discuss how one can use this observable to set constraints on the density parameters of the universe by using a specific spatial topology along with type Ia supernovae and X-ray gas mass fraction data sets.

scholarly journals Spatial variation of fundamental constants: Testing models with thermonuclear supernovae

2018 ◽  
Vol 27 (09) ◽  
pp. 1850099 ◽  
Author(s):  
C. Negrelli ◽  
L. Kraiselburd ◽  
S. Landau ◽  
E. García-Berro
Keyword(s):  
Spatial Variation ◽  
Fundamental Constant ◽  
Dipole Model ◽  
Type Ia Supernovae ◽  
Fundamental Constants ◽  
Speed Of Light ◽  
Significant Difference ◽  
Type Ia ◽  
Ia Supernovae ◽  
Peak Luminosity

Since Dirac stated his Large Number Hypothesis the space-time variation of fundamental constants has been an active subject of research. Here we analyze the possible spatial variation of two fundamental constants: the fine structure constant [Formula: see text] and the speed of light [Formula: see text]. We study the effects of such variations on the luminosity distance and on the peak luminosity of Type Ia supernovae (SNe Ia). For this, we consider the change of each fundamental constant separately and discuss a dipole model for its variation. Elaborating upon our previous work, we take into account the variation of the peak luminosity of Type Ia supernovae resulting from the variation of each of these fundamental constants. Furthermore, we also include the change of the energy release during the explosion, which was not studied before in the literature. We perform a statistical analysis to compare the predictions of the dipole model for [Formula: see text] and [Formula: see text] variation with the Union 2.1 and JLA compilations of SNe Ia. Allowing the nuisance parameters of the distance estimator [Formula: see text] and the cosmological density matter [Formula: see text] to vary. As a result of our analysis, we obtain a first estimate of the possible spatial variation of the speed of light [Formula: see text]. On the other hand, we find that there is no significant difference between the several phenomenological models studied here and the standard cosmological model, in which fundamental constants do not vary at all. Thus, we conclude that the actual set of data of Type Ia supernovae does not allow to verify the hypothetical spatial variation of fundamental constants.

scholarly journals Testing the Speed of Light over Cosmological Distances: The Combination of Strongly Lensed and Unlensed Type Ia Supernovae

2018 ◽  
Vol 867 (1) ◽  
pp. 50 ◽  
Author(s):  
Shuo Cao ◽  
Jingzhao Qi ◽  
Marek Biesiada ◽  
Xiaogang Zheng ◽  
Tengpeng Xu ◽  
...  
Keyword(s):  
Type Ia Supernovae ◽  
Speed Of Light ◽  
Type Ia ◽  
Ia Supernovae

scholarly journals A New Method to Calibrate the Magnitudes of Type Ia Supernovae at Maximum Light

2006 ◽  
Vol 647 (1) ◽  
pp. 501-512 ◽  
Author(s):  
Jose Luis Prieto ◽  
Armin Rest ◽  
Nicholas B. Suntzeff
Keyword(s):  
New Method ◽  
Type Ia Supernovae ◽  
Maximum Light ◽  
Type Ia ◽  
Ia Supernovae

scholarly journals Carnegie Supernova Project-II: A New Method to Photometrically Identify Sub-types of Extreme Type Ia Supernovae

2020 ◽  
Vol 895 (1) ◽  
pp. L3 ◽  
Author(s):  
C. Ashall ◽  
J. Lu ◽  
C. Burns ◽  
E. Y. Hsiao ◽  
M. Stritzinger ◽  
...  
Keyword(s):  
New Method ◽  
Type Ia Supernovae ◽  
Extreme Type ◽  
Type Ia ◽  
Ia Supernovae

scholarly journals SNe data analysis in variable speed of light cosmologies without cosmological constant

2014 ◽  
Vol 29 (24) ◽  
pp. 1450103 ◽  
Author(s):  
Pengfei Zhang ◽  
Xinhe Meng
Keyword(s):  
Dark Energy ◽  
Scale Factor ◽  
Model Parameters ◽  
Type Ia Supernovae ◽  
Distance Modulus ◽  
Data Sets ◽  
Variable Speed ◽  
Speed Of Light ◽  
Type Ia ◽  
Ia Supernovae

In this work, we aim to show the possibilities of the variable speed of light (VSL) theory in explaining the type Ia supernovae (SNe) observations without introducing dark energy. The speed of light is assumed to be scale factor-dependent, which is the most popular assumption in VSL theory. We show the modified calculation of the distance modulus and the validity of the redshift-scale factor relation in VSL theory. Three different models of VSL are tested SNe data-sets with proper constraints on the model parameters. The comparison of the three models and flat ΛCDM in distance modulus is showed. Some basic problems and the difficulties of the confirmation of the VSL theory are also discussed.

Hard X‐Rays and Gamma Rays from Type Ia Supernovae

1998 ◽  
Vol 492 (1) ◽  
pp. 228-245 ◽  
Author(s):  
P. Hoflich ◽  
J. C. Wheeler ◽  
A. Khokhlov
Keyword(s):  
Gamma Rays ◽  
Type Ia Supernovae ◽  
X Rays ◽  
Type Ia ◽  
Ia Supernovae

scholarly journals Gravitational Collapse versus Thermonuclear Explosion of Degenerate Stellar Cores

1994 ◽  
Vol 147 ◽  
pp. 186-213
Author(s):  
J. Isern ◽  
R. Canal
Keyword(s):  
Neutron Star ◽  
White Dwarfs ◽  
Light Curves ◽  
Type Ia Supernovae ◽  
Radioactive Elements ◽  
Border Line ◽  
Thermonuclear Explosion ◽  
Type Ia ◽  
Γ Rays ◽  
Ia Supernovae

AbstractIn this paper we review the behavior of growing stellar degenerate cores. It is shown that ONeMg white dwarfs and cold CO white dwarfs can collapse to form a neutron star. This collapse is completely silent since the total amount of radioactive elements that are expelled is very small and a burst of γ-rays is never produced. In the case of an explosion (always carbonoxygen cores), the outcome fits quite well the observed properties of Type Ia supernovae. Nevertheless, the light curves and the velocities measured at maximum are very homogeneous and the diversity introduced by igniting at different densities is not enough to account for the most extreme cases observed. It is also shown that a promising way out of this problem could be the He-induced detonation of white dwarfs with different masses. Finally, we outline that the location of the border line which separetes explosion from collapse strongly depends on the input physics adopted.

scholarly journals A Novel Color Parameter as a Luminosity Calibrator for Type Ia Supernovae

2005 ◽  
Vol 620 (2) ◽  
pp. L87-L90 ◽  
Author(s):  
Xiaofeng Wang ◽  
Lifan Wang ◽  
Xu Zhou ◽  
Yu-Qing Lou ◽  
Zongwei Li
Keyword(s):  
Type Ia Supernovae ◽  
Color Parameter ◽  
Type Ia ◽  
Ia Supernovae
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