演講資訊

Prof. Pan (IANCU)

""First Hubble diagram and cosmological constraints using superluminous supernova" by Inserra et al. "

時間/地點: 2020-12-30 12:10 [S4-1013]

摘要:

We present the first Hubble diagram of superluminous supernovae (SLSNe) out to a redshift of two, together with constraints on the matter density, ΩM , and the dark energy equation-of-state parameter, w(≡p/ρ) . We build a sample of 20 cosmologically useful SLSNe~I based on light curve and spectroscopy quality cuts. We confirm the robustness of the peak decline SLSN~I standardization relation with a larger dataset and improved fitting techniques than previous works. We then solve the SLSN model based on the above standardisation via minimisation of the χ2 computed from a covariance matrix which includes statistical and systematic uncertainties. For a spatially flat Λ CDM cosmological model, we find ΩM=0.44+0.21−0.21 , with a rms of 0.28 mag for the residuals of the distance moduli. For an w0wa CDM cosmological model, the addition of SLSNe~I to a `baseline' measurement consisting of Planck temperature and WMAP polarization of the cosmic microwave background (CMB) fluctuation together with type Ia supernovae, results in a small improvement in the constraints of w0 and wa of 4\%. We present simulations of future surveys with 847 SLSNe I and show that such a sample can deliver cosmological constraints in a flat Λ CDM model with the same precision (considering only statistical uncertainties) as current surveys that use type Ia supernovae, while providing an improvement of 15\% in the constraints on the time variation of dark energy, w0 and wa . This paper represents the proof-of-concept for superluminous supernova cosmology, and demonstrates they can provide an independent test of cosmology in the high-redshift ( z>1 ) universe.

You may refer to the following link for more details: https://ui.adsabs.harvard.edu/abs/2020arXiv200412218I/abstract

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