scholarly journals Reaffirmation of cosmological oscillations in the scale factor from the Pantheon compilation of 1048 Type Ia supernovae

2020 ◽  
Vol 494 (2) ◽  
pp. 2158-2165 ◽  
Author(s):  
H I Ringermacher ◽  
L R Mead
Keyword(s):  
Dark Matter ◽  
Scalar Field ◽  
Energy Density ◽  
Friedmann Equation ◽  
Scale Factor ◽  
Field Energy ◽  
Type Ia Supernovae ◽  
Density Parameter ◽  
Type Ia ◽  
Ia Supernovae

ABSTRACT We observe damped temporal oscillations in the scale factor at a dominant frequency of ∼7 cycles/Hubble-time in the Pantheon compilation of 1048 Type Ia supernovae (SNe Ia). The residual oscillations observed in the Pantheon data closely match and reaffirm our initial observation of oscillations from earlier SNe data (primarily SNLS3 data of Conley 2011) at 2σ confidence. The nearly identical shapes in amplitude, frequency, phase, and damping constant makes it highly likely that the signal is real. Furthermore, two-thirds of the Pantheon SNe cover different portions of the sky compared with SNLS3 strengthening this conclusion. Our model describing the oscillation, presented in an earlier paper, is a simple scalar field harmonic oscillator coupled to the Lambda cold dark matter (ΛCDM) Friedmann equation, but carried into the present epoch. The scalar field energy density plays the role of the dark matter energy density in ΛCDM cosmology, fits well as an average, and closely matches the present dark matter density parameter, suggesting the oscillation plays a role in the dark matter sector. Temporal oscillations in the scale factor and its derivative, as described in this work, would also induce temporal oscillations of the Hubble parameter.

scholarly journals RECONSTRUCTION OF 5D COSMOLOGICAL MODELS FROM RECENT OBSERVATIONS

2007 ◽  
Vol 16 (10) ◽  
pp. 1573-1579
Author(s):  
CHENGWU ZHANG ◽  
LIXIN XU ◽  
YONGLI PING ◽  
HONGYA LIU
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Equation Of State ◽  
Cosmological Solution ◽  
Type Ia Supernovae ◽  
Shift Parameter ◽  
Type Ia ◽  
Ia Supernovae ◽  
Best Fit ◽  
The Universe

We use a parameterized equation of state (EOS) of dark energy to a 5D Ricci-flat cosmological solution and suppose the universe contains two major components: dark matter and dark energy. Using the recent observational datasets: the latest 182 type Ia Supernovae Gold data, the three-year WMAP CMB shift parameter and the SDSS baryon acoustic peak, we obtain the best fit values of the EOS and two major components' evolution. We find that the best fit EOS crosses -1 in the near past where z ≃ 0.07, the present best fit value of wx(0) < -1 and for this model, the universe experiences the acceleration at about z ≃ 0.5.

scholarly journals VARIABLE CHAPLYGIN GAS: CONSTRAINTS FROM CMBR ANDSNe Ia

2006 ◽  
Vol 15 (07) ◽  
pp. 1089-1098 ◽  
Author(s):  
GEETANJALI SETHI ◽  
SUSHIL K. SINGH ◽  
PRANAV KUMAR ◽  
DEEPAK JAIN ◽  
ABHA DEV
Keyword(s):  
Equation Of State ◽  
Positive Function ◽  
Chaplygin Gas ◽  
Scale Factor ◽  
Type Ia Supernovae ◽  
Data Set ◽  
Cosmological Scale ◽  
Type Ia ◽  
Ia Supernovae

We constrain the parameters of the variable Chaplygin gas model, using the location of peaks of the CMBR spectrum and the SNe Ia "gold" data set. The equation of state of the model is P = -A(a)/ρ, where A(a) = A0a-nis a positive function of the cosmological scale factor a, A0and n> being constants. The variable Chaplygin gas interpolates from the dust-dominated era to the quintessence dominated era. The model is found to be compatible with current type Ia supernovae data and the location of the first peak if the values of Ωmand n lie in the interval [0.017, 0.117] and [-1.3, 2.6], respectively.

scholarly journals Type Ia supernovae from dark matter core collapse

2019 ◽  
Vol 100 (3) ◽  
Author(s):  
Ryan Janish ◽  
Vijay Narayan ◽  
Paul Riggins
Keyword(s):  
Dark Matter ◽  
Type Ia Supernovae ◽  
Core Collapse ◽  
Type Ia ◽  
Ia Supernovae

Overview of astroparticle physics and dark matter searches

2007 ◽  
Vol 22 (31) ◽  
pp. 5735-5746
Author(s):  
Nathalie Palanque-Delabrouille
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Acoustic Oscillation ◽  
Type Ia Supernovae ◽  
Clusters Of Galaxies ◽  
Astroparticle Physics ◽  
The Status ◽  
Type Ia ◽  
Ia Supernovae ◽  
The Impact

We present a general overview of recent results in the searches for dark matter and dark energy. We discuss the observation of the collision between two clusters of galaxies, and the impact this has on the relevance of dark matter. We then present the final results from microlensing experiments, which aimed at detecting dark baryonic objects in the halo of our galaxy, and the status of direct searches for WIMPs. We present the evidence for dark energy which initially comes from experiments dedicated to the study of distant type Ia supernovae. The measure of the baryon acoustic oscillation, an independent probe of the evolution of our universe that has recently brought interesting constraints, is finally described.

scholarly journals BAYESIAN ANALYSIS OF THE CHAPLYGIN GAS AND COSMOLOGICAL CONSTANT MODELS USING THE SNe Ia DATA

2004 ◽  
Vol 13 (04) ◽  
pp. 669-693 ◽  
Author(s):  
R. COLISTETE ◽  
J. C. FABRIS ◽  
S. V. B. GONÇALVES ◽  
P. E. DE SOUZA
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Confidence Level ◽  
Cold Dark Matter ◽  
Chaplygin Gas ◽  
Type Ia Supernovae ◽  
Λcdm Model ◽  
Type Ia ◽  
Ia Supernovae ◽  
The Universe

The type Ia supernovae observational data are used to estimate the parameters of a cosmological model with cold dark matter and the Chaplygin gas. This exotic gas, which is characterized by a negative pressure varying with the inverse of density, represents in this model the dark energy responsible for the acceleration of the Universe. The Chaplygin gas model depends essentially on four parameters: the Hubble constant, the velocity of the sound of the Chaplygin gas, the curvature of the Universe and the fraction density of the Chaplygin gas and the cold dark matter. The Bayesian parameter estimation yields [Formula: see text] and [Formula: see text]. These and other results indicate that a Universe completely dominated by the Chaplygin gas is favoured, what reinforces the idea that the Chaplygin gas may unify the description for dark matter and dark energy, at least as the type Ia supernovae data are concerned. A closed and accelerating Universe is also favoured. The Bayesian statistics indicates that the Chaplygin gas model is more likely than the standard cosmological constant (ΛCDM) model at 55.3% confidence level when an integration on all free parameters is performed. Assuming the spatially flat curvature, this percentage mounts to 65.3%. On the other hand, if the density of dark matter is fixed at zero value, the Chaplygin gas model becomes more preferred than the ΛCDM model at 91.8% confidence level. Finally, the hypothesis of flat Universe and baryonic matter (Ωb0=0.04) implies a Chaplygin gas model preferred over the ΛCDM at a confidence level of 99.4%.

scholarly journals DARK MATTER ADMIXED TYPE Ia SUPERNOVAE

2015 ◽  
Vol 812 (2) ◽  
pp. 110 ◽  
Author(s):  
S.-C. Leung ◽  
M.-C. Chu ◽  
L.-M. Lin
Keyword(s):  
Dark Matter ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Ia Supernovae
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