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There are some approaches, either based on General Relativity (GR) ormodified gravity, that use galaxy rotation curves to derive the matter densityof the corresponding galaxy, and this procedure would either indicate a partialor a complete elimination of dark matter in galaxies. Here we review theseapproaches, clarify the difficulties on this inverted procedure, present amethod for evaluating them, and use it to test two specific approaches that arebased on GR: the Cooperstock-Tieu (CT) and the Balasin-Grumiller (BG)approaches. Using this new method, we find that neither of the testedapproaches can satisfactorily fit the observational data without dark matter.The CT approach results can be significantly improved if some dark matter isconsidered, while for the BG approach no usual dark matter halo can improve itsresults.

A method for evaluating models that use galaxy rotation curves to derive the density profiles