FORMACIÓN DE ESTRUCTURAS CON GRAVEDAD MODIFICADA A GRAN ESCALA CON CAMPO TIPO YUKAWA INVERSO UYF

The formation of galaxy clusters and superclusters is studied in the formalism of Jeans theory with modified gravity (particularly an inverse Yukawa field), adding the dependence on the size of stellar clouds. The estimates agree with observations for average sizes of molecular clouds and spiral galaxies; in addition, the formation of alternating regions of stability and fragmentation for intercloud gas is predicted, with high stability for large clouds (> 10 Mpc) of intergalactic gas (with densities no≤ 10−3 cm−3) and a high fragmentation rate for smaller clouds (90 kpc < r < 10 Mpc). The Hubble expansion is naturally included in the formation of large-scale structure in the Universe without modifying the well-known description for stellar scales and high densities. The new description is a generalization of Jeans theory without invoking non-baryonic dark matter.Key words: Modified gravitation, structure formation, Jeans theory.