ELFT HÍRADÓ

[vidakris AT konkoly.hu]

Szemináriumi meghívó / Invitation to a seminar
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CSFK CSI SZEMINÁRIUM / KONKOLY OBSERVATORY SEMINAR

Date: May 30 (Thursday) 14:00


Maria Dainotti
National Astronomical Observatory of Japan

GRBs and other probes for cosmology

Cosmological models and their parameters are widely debated, especially about 
whether the current discrepancy between the values of the Hubble constant, H 
0, obtained by Type Ia supernovae (SNe Ia) and the Planck data from the 
cosmic microwave background radiation could be alleviated when alternative 
cosmological models are considered. Thus, combining high-redshift probes, 
such as gamma-ray bursts (GRBs) and quasi-stellar objects (QSOs, or quasars), 
together with baryon acoustic oscillations and SNe Ia is important to assess 
the viability of these alternative models and whether they can cast further 
light on the Hubble tension. In this work, for GRBs, we use a 
three-dimensional relation between the peak prompt luminosity, the rest-frame 
time at the end of the X-ray plateau, and its corresponding luminosity in 
X-rays: the 3D Dainotti fundamental plane relation. Regarding QSOs, we use 
the Risaliti-Lusso relation among the UV and X-ray luminosities for a sample 
of 2421 sources. We corre
 ct both the QSO and GRB relations by accounting for selection and 
evolutionary effects with a reliable statistical method. We here use both the 
traditional Gaussian likelihoods ( LG 𝐿𝐺 ) and the new best-fit likelihoods (
𝐿𝑁 ) to infer cosmological parameters of nonflat Lambda cold dark matter 
(ΛCDM) and flat wCDM models. We obtain for all the parameters reduced 
uncertainties, up to 35% for H 0, when applying the new 𝐿𝑁 likelihoods in 
place of the Gaussian ones. Our results remain consistent with a flat ΛCDM 
model, although with a shift of the dark energy parameter w toward w < -1 and 
a curvature density parameter toward Ω k < 0.

The seminar will be held live in the Detre hall with audience, but also 
streamed online via Zoom. If you are unable to attend the presentation in 
person, you can join us via this link
https://us06web.zoom.us/j/82806911982?pwd=SVZpT0syQ1J6dHBvSkF4N2dXNEQ0dz09
or the meeting ID: 828 0691 1982 and passcode: 206265



Everyone is welcome!

Krisztián Vida, Ramon Brasser
organizers
https://konkoly.hu/k-szeminariumok