Superluminous quasars and mesolensing

Observed magnitudes of many quasars with redshifts exceeding z = 5 correspond to luminosities L bol > 10 14 L ⊙ . Thestandard mechanism of quasar energy release by accretion suggests that masses of superluminous quasars should exceed10 10 M ⊙ . On the other hand, the age of these objects in the standard cosmological model is below one billion years, whichis too short to explain their formation in the early Universe. Many quasars are known to be gravitationally lensed; showingmultiple images of the same object. In the case of remote quasars with no multiple images, it is still possible that they arealso gravitationally lensed by foreground objects of intermediate masses, such as globular clusters or dwarf galaxies. Suchmesolensing would result in essential amplification of quasar brightnesses, subject to geometrical configuration betweenthe lens and the lensed object. Here we estimate the fraction of quasars whose brightness might have been amplified bygravitational lensing.