Galaxy interactions: dark matter vs. Modified Newtonian dynamics (MOND)
  (doctoral thesis of Michal Bilek, finished on June 19, 2015)
  MOND is an observational rule for predicting the acceleration of stars and
galaxies from the distribution of the visible matter. It possibly stems from a
new law of physics. I list the theoretical aspects of MOND, its achievements
and problems. MOND has been tested mainly in disc galaxies so far. Its tests in
elliptical galaxies are rare because the MOND effects are small for them in the
parts observable by the conventional methods. In the thesis, I explain the
methods and ideas I developed for testing MOND in the ellipticals using stellar
shells. Moreover, the shells enable us to test MOND for stars in radial orbits
for the first time. The shells are results of galactic interactions. I discuss
the shell formation mechanisms and summarize the findings from shell
observations and simulations.
  The thesis contains as yet unpublished results mainly in: 1) the introduction
of Sect. 3 (the expected differences in the shell morphology in the Newtonian
dynamics with dark matter and in MOND), and 2) Sect. 2.4.1 (formulas for
modeling the evolution of shell radii).
