  Bulges can be classified into classical and pseudobulges; the former are
considered to be end products of galactic mergers and the latter to form via
secular evolution of galactic disks. Observationally, bulges of disk galaxies
are mostly pseudobulges, including the Milky Way's. We here show, by using
self-consistent cosmological simulations of galaxy formation, that the
formation of pseudobulges of Milky Way-sized disk galaxies has mostly completed
before disk formation; thus the main channel of pseudobulge formation is not
secular evolution of disks. Our pseudobulges form by rapid gas supply at
high-redshift and their progenitors would be observed as high-redshift disks.
