Adjacent to the Local Group of galaxies, the M81 group of galaxies offers a good opportunity for a verification of the dark matter hypothesis underlying the standard model of cosmology (the Lambda Cold Dark Matter, LCDM, or Lambda Warm Dark Matter models).
M81 (free download from the NASA / IPAC Website) at a distance of 11-12 Million lightyears (approximately 3.6 Mpc).
Being accompanied by M82 and NGC 3077, it is clear from radioastronomical observations that both companions must have passed the central galaxy M81 closely, within about 30 thousand pc and within the recent cosmological past, that is within a few hundred million years ago. In fact, all three galaxies are embedded in a huge cloud of intergalactic hydrogen (namely the north tidal bridge between M81 and M82, and the south tidal bridge between M81 and NGC 3077; http://www.nrao.edu/pr/2008/m81clouds/). Although more recent observational work exists, the dynamical evolution of this group has not been investigated theoretically since 1999. Based on the assumptions of the dark matter hypothesis, the last published such work could not find solutions of the group’s dynamical history with dark matter halos.
In September 2012 I joined the team of Prof. Dr. Pavel Kroupa (University of Bonn https://astro.uni-bonn.de/~pavel/) establishing a project investigating the dynamical evolution of the inner M81 group of galaxies concerning the fundamental question whether dark matter exists. We have carried out extensive simulations and published our results with MNRAS (Monthly Notices of the Royal Astronomical Society, Oxford): http://dx.doi.org/10.1093/mnras/stw3381.
Meanwhile we have transferred our methodology to the Hickson compact groups of galaxies and presented the preliminary results at the international conference "Cosmology on Small Scales 2018" (http://CSS2018.math.cas.cz, direct link to the proceedings (PDF download, our contribution to be found on page 30) http://css2018.math.cas.cz/proceedingsCSS2018.pdf).
The results obtained strictly disfavour the existence of dark matter halos and therefore contradict the standard model of cosmology.
Current research activities on the dynamical behaviour of the Magellanic Clouds - the major satellites of our galaxy - point very much into the same direction. We are in the process of publishing our results soon.
(University of Bonn)
Further to the doubts regarding the existence of dark matter I want to mention my most recent publication: From an epistemological point of view, there is a possible logical constraint on the validity of Einstein's theory of General Relativity for very strong gravitational forces (https://doi.org/10.12988/astp.2021.91510), therefore at least questioning the Big Bang as an essential theoretical part of the cosmological standard model. As mentioned, I worked out a logical constraint, which is not just a matter of questioning excessive extrapolations.
Formerly being concerned with quantum mechanical few body physics, this is the list of my publications regarding this field of research: