A case against an X-shaped structure in the Milky Way young bulge
  CONTEXT. A number of recent papers have claimed the discovery of an X-shape
structure in the bulge of our Galaxy in the population of the red clumps.
  AIMS. We endeavor to analyze the stellar density of bulge stars in the same
regions using a different stellar population that is characteristic of the
young bulge ($\lesssim 5$ Gyr). Particularly, we use F0-F5 main-sequence stars
with distances derived through photometric parallax.
  METHODS. We extract these stars from extinction-corrected color-magnitude
diagrams in the near-infrared of VISTA-VVV data in some bulge regions and
calculate the densities along the line of sight. We take the uncertaintity in
the photometric parallax and the contamination of other sources into account,
and we see that these errors do not avoid the detection of a possible double
peak along some lines of sight as expected for a X-shape bulge if it existed.
  RESULTS. Only a single peak in the density distribution along the line of
sight is observed, so apparently there is no X-shape structure for this
population of stars. Nonetheless, the effects of the dispersion of absolute
magnitudes in the selected population might be an alternative explanation,
although in principle these effects are insufficient to explain this lack of
double peak according to our calculations.
  CONCLUSIONS. The results of the present paper do not demonstrate that
previous claims of X-shaped bulge using only red clump stars are incorrect, but
there are apparently some puzzling questions if we want to maintain the
validity of both the red-clump results and the results of this paper.
