No description available.

Zugl.: Stuttgart, Univ., Diss., 2006. / Druckausg. bei Hut, München erschienen.

No description available.

Diss. Bern.

Thesis--Göteborg. / Includes abstract. Includes reprints of author's articles. Extra t.p. with thesis statement inserted. Includes bibliographical references.

Thesis--Göteborg. / Includes abstract. Includes reprints of author's articles. Extra t. p. with thesis statement inserted. Includes bibliographies.

No description available.

No description available.

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.

As an alternative to dark matter, Modified Newtonian Dynamics (MOND) can explain dynamical measurements of galaxies on small scales. It is, however, unclear whether MOND still works for galaxies on the large scale. In this study, we use galaxy- galaxy (g-g) weak lensing measurements to examine MOND in the outer regions of galaxies. First, we study the amplitude of the weak gravitational lensing signal as a function of stellar mass around relatively isolated galaxies. We find that our measurements are inconsistent with the predictions from MOND. Second, we examine whether MOND can produce an anisotropic lensing signal as observed in the real data. Starting with a mass distribution of an extremely high ellipticity, we find it is very hard for MOND to reproduce the observed extensive anisotropic lensing signal from only the visible mass. Because the g-g lensing is measured at radii of up to hundreds of kiloparsecs, these two tests indicate that MOND does not work in outer regions of galaxies. Our study casts serious doubt on the notation that MOND can convincingly prove itself as a viable alternative to dark matter.