According to the modern cosmological paradigm, about 2/3 of the energy of the Universe is in the dark form and about 5/6 of the matter is invisible. However, numerous recent attempts to detect independently the dark-matter particles failed, and a number of other problems with the existence of dark energy and dark matter (such as the anomalous friction in the dark-matter halos of galaxies, etc.) become now more and more obvious. All these troubles raise the question if the "dark" substance is merely a result of excessive extrapolations involved in the theoretical analysis? So, it is timely to gather specialists from various branches of astronomy and astrophysics to discuss these issues.
Topics: Mathematical aspects of the extrapolations used in cosmology, Arguments for and against dark matter, and revisiting the foundations of physics, Alternative models for dark matter and dark energy, A systematic discord in the value of the Hubble constant derived by different methods, Theoretical possibility and observational evidence for small-scale cosmological effects, Complementary redshifts of non-cosmological nature, Quantum effects on the early universe and their observational imprints at the present time