We perform an independent search for annual modulation in the recently released COSINE-100 data, which could be induced by dark matter scatterings. We test the hypothesis that the data contains a sinusoidal modulation against the null hypothesis, that the data consists of only background. We compare the significance using frequentist method, information theoretic techniques (such as AIC and BIC), and finally a Bayesian model comparison technique. Both the frequentist and Bayesian techniques reveal no significant differences between the two hypotheses, whereas the null hypothesis is slightly favored according to AIC and BIC-based tests. This is the first proof of principles demonstration of application of Bayesian and information theory based techniques to COSINE-100 data to assess the significance of annual modulation.
In this work, we investigate what extent the cosmological parameters can be constrained to when the redshift drift data of Square Kilometre Array (SKA) are used alone and what will happen when the European Extremely Large Telescope (E-ELT) and SKA mock data are combined. The $\Lambda$CDM model is chosen as a reference model to reach our aims. We find that using the SKA1-only mock data, the $\Lambda$CDM model can be loosely constrained, while the model can be well constrained when the SKA2-only mock data are used. When the combination of SKA and E-ELT mock data are considered, the constraints can be significantly improved almost as good as the data combination of the type Ia supernovae observation, the cosmic microwave background observation, and the baryon acoustic oscillations observation. Furthermore, we also investigate in the future what role the redshift drift data of SKA will play in the cosmological parameter estimation. We use four dark energy models, namely, the $\Lambda$CDM model, the $w$CDM model, the CPL model, and the HDE model, as examples to make the analysis. These models are favored by the current observations well. we find that the redshift drift measurement of SKA could help to significantly improve the constraint on dark energy and could break the degeneracy existing between the cosmological parameters. Therefore, we conclude that redshift-drift observation of SKA would provide a good improvement in the cosmological parameter estimation in the future and have the enormous potential to be one of the most competitive cosmological probes in constraining dark energy.