Vizniuk O. Dark energy and dark matter as manifestations of gravity on the brane

New properties of the braneworld model with induced gravity are revealed and investigated; the obtained results are applied for an explanation of the effects of dark energy and dark matter. It was shown that, for a large region of parameter space, the universe in the braneworld model during early cosmological epochs behaves in the same way as in the standart model LCDM. It was also derived an exact system of equations describing scalar cosmological perturbations on a brane. Depending upon the choice of boundary conditions, perturbations on the brane either grow rapidly (thus leading to instability) or moderately (parameter region of stability). In the region of parameters corresponding to stability, the rate of growth of the cosmological perturbations may be consistent with the formation of the large-scale structure of the universe. It was found new spherically symmetric solutions to the braneworld equations and it was shown that the constant values of the rotational velocities in the halo of spiralgalaxies can be explained in the braneworld model without dark matter component. Corrections to the Newton's law on the visible brane were computed In the two-brane background with matter on the hidden brane taken into account.