Width of the 511 keV line from the bulge of the galaxy

In this paper I present the detail estimations for the width of the 511 keV line produced by a mechanism when dark matter is represented by macroscopically large dense nuggets. I argue that the width of 511 keV emission in this mechanism is very narrow (in a few keV range) in agreement with all observations. The dominant mechanism of the annihilation in this case is the positronium formation e⁺e^-→S01→2γ rather than a direct e⁺e^-→2γ annihilation. I also discuss some generic features of the γ rays spectrum (in few MeV range) resulting from this mechanism.