  In the standard model of core accretion, the cores of the giant planets form
by the accretion of planetesimals. In this scenario, the evolution of the
planetesimal population plays an important role in the formation of massive
cores. Recently, we studied the role of planetesimal fragmentation in the in
situ formation of a giant planet. However, the exchange of angular momentum
between the planet and the gaseous disk causes the migration of the planet in
the disk. In this new work, we incorporate the migration of the planet and
globally study the role of planet migration in the formation of a massive core
when the population of planetesimals evolves by planet accretion, migration due
to the nebular drag, and fragmentation due to planetesimal collisions.
