Evolution of Galaxy Star Formation and Metallicity: Impact on Double
  Compact Objects Mergers
  We study the impact of different galaxy statistics and empirical metallicity
scaling relations on the merging rates and on the properties of compact objects
binaries. First, we analyze the similarities and differences of using the star
formation rate functions or the stellar mass functions as galaxy statistics for
the computation of the cosmic star formation rate density. Then we investigate
the effects of adopting the Fundamental Metallicity Relation or a classic Mass
Metallicity Relation to assign metallicity to galaxies with given properties.
We find that when the Fundamental Metallicity Relation is exploited, the bulk
of the star formation occurs at relatively high metallicities even at high
redshift; the opposite holds when the Mass Metallicity Relation is employed,
since in this case the metallicity at which most of the star formation takes
place strongly decreases with redshift. We discuss the various reasons and
possible biases originating this discrepancy. Finally, we show the impact that
these different astrophysical prescriptions have on the merging rates and on
the properties of compact objects binaries; specifically, we present results
for the redshift dependent merging rates and for the chirp mass and time delay
distributions of the merging binaries.
