scholarly journals Constraining neutrino mass and dark energy with peculiar velocities and lensing dispersions of Type Ia supernovae

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
Aniket Agrawal ◽  
Teppei Okumura ◽  
Toshifumi Futamase
2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Hamid Reza Amiri ◽  
Amin Salehi ◽  
Amir Hossein Noroozi

AbstractIn this paper, we investigate the constraints on the total neutrino mass $$\sum m_{\nu }$$ ∑ m ν in a cosmological model in which dark energy and neutrinos are coupled such that the mass of the neutrinos and potentials are function of the scalar field as $$m_{\nu }=m_{0}\exp (\frac{\alpha \phi }{m_{pl}})$$ m ν = m 0 exp ( α ϕ m pl ) and $$V(\phi )=m_{pl}^{4}\exp (\frac{-\lambda \phi }{m_{pl}})$$ V ( ϕ ) = m pl 4 exp ( - λ ϕ m pl ) respectively. The observational data used in this work include the type Ia supernovae (SN) observation (Pantheon compilation), CC, CMB and BAO data. We find that the neutrino mass is tightly constrained to $$\sum m_{\nu }< 0.125$$ ∑ m ν < 0.125  eV 95% Confidence Level (C.L.) and the effective extra relativistic degrees of freedom to be $$N_{eff}=2.955^{+0.11}_{-0.12}$$ N eff = 2 . 955 - 0.12 + 0.11 68% C.L in agreement with the Standard Model prediction $$ N_{eff} = 3.046$$ N eff = 3.046 , matter-radiation equality, $$z_{eq}=3389^{+24}_{25}$$ z eq = 3389 25 + 24 (68% C.L). These results are in good agreement with the results of Planck 2018 where the limit of the total neutrino mass is $$\sum m_{\nu }<0.12$$ ∑ m ν < 0.12 eV (95% C.L., TT, TE, EE + lowE + lensing + BAO) , $$N_{eff}=2.99^{+0.17}_{-0.17}$$ N eff = 2 . 99 - 0.17 + 0.17 (68% C.L., TT, TE, EE + lowE + lensing + BAO) and $$z_{eq}=3387^{+21}_{21}$$ z eq = 3387 21 + 21 (68% C.L TT, TE, EE + lowE + lensing + BAO).


2005 ◽  
Vol 192 ◽  
pp. 525-533
Author(s):  
Weidong Li ◽  
Alexei V. Filippenko

SummaryObservations of Type Ia supernovae (SNe Ia) reveal correlations between their luminosities and light-curve shapes, and between their spectral sequence and photometric sequence. Assuming SNe Ia do not evolve at different redshifts, the Hubble diagram of SNe Ia may indicate an accelerating Universe, the signature of a cosmological constant or other forms of dark energy. Several studies raise concerns about the evolution of SNe Ia (e.g., the peculiarity rate, the rise time, and the color of SNe Ia at different redshifts), but all these studies suffer from the difficulties of obtaining high-quality spectroscopy and photometry for SNe Ia at high redshifts. There are also some troubling cases of SNe Ia that provide counter examples to the observed correlations, suggesting that a secondary parameter is necessary to describe the whole SN Ia family. Understanding SNe Ia both observationally and theoretically will be the key to boosting confidence in the SN Ia cosmological results.


2019 ◽  
Vol 486 (2) ◽  
pp. 2184-2196 ◽  
Author(s):  
E Macaulay ◽  
R C Nichol ◽  
D Bacon ◽  
D Brout ◽  
T M Davis ◽  
...  

ABSTRACT We present an improved measurement of the Hubble constant (H0) using the ‘inverse distance ladder’ method, which adds the information from 207 Type Ia supernovae (SNe Ia) from the Dark Energy Survey (DES) at redshift 0.018 &lt; z &lt; 0.85 to existing distance measurements of 122 low-redshift (z &lt; 0.07) SNe Ia (Low-z) and measurements of Baryon Acoustic Oscillations (BAOs). Whereas traditional measurements of H0 with SNe Ia use a distance ladder of parallax and Cepheid variable stars, the inverse distance ladder relies on absolute distance measurements from the BAOs to calibrate the intrinsic magnitude of the SNe Ia. We find H0 = 67.8 ± 1.3 km s−1 Mpc−1 (statistical and systematic uncertainties, 68 per cent confidence). Our measurement makes minimal assumptions about the underlying cosmological model, and our analysis was blinded to reduce confirmation bias. We examine possible systematic uncertainties and all are below the statistical uncertainties. Our H0 value is consistent with estimates derived from the Cosmic Microwave Background assuming a ΛCDM universe.


2007 ◽  
Vol 16 (10) ◽  
pp. 1573-1579
Author(s):  
CHENGWU ZHANG ◽  
LIXIN XU ◽  
YONGLI PING ◽  
HONGYA LIU

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.


1992 ◽  
Vol 103 ◽  
pp. 379 ◽  
Author(s):  
Douglas L. Miller ◽  
David Branch

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