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We perform a comparative numerical hydrodynamics study of embeddedprotostellar disks formed as a result of the gravitational collapse of cloudcores of distinct mass (M_cl=0.2--1.7 M_sun) and ratio of rotational togravitational energy (\beta=0.0028--0.023). An increase in M_cl and/or \betaleads to the formation of protostellar disks that are more susceptible togravitational instability. Disk fragmentation occurs in most models but itseffect is often limited to the very early stage, with the fragments beingeither dispersed or driven onto the forming star during tens of orbitalperiods. Only cloud cores with high enough M_cl or \beta may eventually formwide-separation binary/multiple systems with low mass ratios and brown dwarf orsub-solar mass companions. It is feasible that such systems may eventuallybreak up, giving birth to rogue brown dwarfs. Protostellar disks of {\it equal}age formed from cloud cores of greater mass (but equal \beta) are generallydenser, hotter, larger, and more massive. On the other hand, protostellar disksformed from cloud cores of higher \beta (but equal M_cl) are generally thinnerand colder but larger and more massive. In all models, the difference betweenthe irradiation temperature and midplane temperature \triangle T is small,except for the innermost regions of young disks, dense fragments, and disk'souter edge where \triangle T is negative and may reach a factor of two or evenmore. Gravitationally unstable, embedded disks show radial pulsations, theamplitude of which increases along the line of increasing M_cl and \beta buttends to diminish as the envelope clears. We find that single stars with adisk-to-star mass ratio of order unity can be formed only from high-\beta cloudcores, but such massive disks are unstable and quickly fragment intobinary/multiple systems.

Embedded protostellar disks around (sub-)solar protostars. I. Disk structure and evolution