1-5 July 2019
Faculty of Physics, University of Warsaw
Europe/Warsaw timezone

Implications of the possible 21-cm line excess at cosmic dawn on dynamics of interacting dark energy

Not scheduled
20m
Faculty of Physics, University of Warsaw

Faculty of Physics, University of Warsaw

conference hall 0.03, Faculty of Physics, University of Warsaw ul. Pasteura 5, 02-093 Warszawa Poland

Speaker

Mr Xin Ren (University of Science and Technology of China)

Description

arXiv:1904.02458v1 [astro-ph.CO]
In this paper we study implications of the possible excess of 21-cm line global signal at the epoch of cosmic dawn on the evolutions of a class of dynamically interacting dark energy (IDE) models. We firstly summarize two dynamical mechanisms in which different background evolutions can exert considerable effects on the 21-cm line global signal. One is the decoupling time of Compton scattering heating, the other stems from the direct change of optical depth due to the different expansion rate of the Universe. After that, we investigate the IDE models to illustrate the tension between the results of Experiment to Detect the Global Epoch of reionization Signature (EDGES) and other experiments. To apply the analyses of these two mechanisms to IDE models, we find that only the optical depth can be significantly changed. Accordingly, in order to relieve the tension by including the effects of the decoupling time of Compton scattering heating, we deduce a possible evolution form for the Hubble parameter within IDE that begins at an early stage around z∼100 and then smoothly evolves to a value at z∼17 which is smaller than that obtained in the standard paradigm. Eventually, we fulfill this scenario by adding an early dark energy dominated stage to the cosmological paradigm described by IDE models, which can alleviate the tension between EDGES and other cosmological observations but cannot completely solve it.

Primary authors

Mr Chunlong Li (University of Science and Technology of China) Mr Xin Ren (University of Science and Technology of China) Prof. Yi-Fu Cai (University of Science and Technology of China) Dr Martiros Khurshudyan (University of Science and Technology of China)

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