Dear all,

We are happy to announce our Friday cosmology seminar, which will be given by our Ph.D. student, Ms. Saboura Zamani. She will be delivering an interesting talk on „Gravitational lensing from clusters of galaxies to test Disformal Couplings Theories”.

Abstract: We investigate the potential existence of a non-minimal coupling between dark matter and gravity using a compilation of galaxy clusters. We focus on the disformal scenario of a non-minimal model with an associated coupling length „L”. Within the Newtonian approximation, this model introduces a modification to the Poisson equation. We have tested the model by examining strong and weak gravitational lensing data available for a selection of 19 high-mass galaxy clusters observed by the CLASH survey.

We have employed a Markov Chain Monte Carlo code to explore the parameter space, and two different statistical approaches to analyse our results: a standard marginalisation and a profile distribution method. Notably, the profile distribution analysis helps to bypass some volume-effects in the posterior distribution and reveals lower Navarro-Frenk-White concentrations and masses in the non-minimal coupling model compared to the general relativity case. We also found a nearly perfect correlation between the coupling constant „L” and the standard Navarro-Frenk-White scale parameter „r_s”, hinting at a compelling link between these two lengths.

Date and Time: 19th January, 12:30 (CET)
Location: Room 403, Institute of Physics, University of Szczecin, ul. Wielkopolska 15,
70-451 Szczecin, Poland
Zoom Link: https://us06web.zoom.us/j/82914566382?pwd=VECl00idcS9o0NjPObCow8Ae454E3B.1