Astro2020 White Paper: On the Origin of the Initial Mass Function
  It is usually assumed that the stellar initial mass function (IMF) takes a
universal form and that there exists a direct mapping between this and the
distribution of natal core masses (the core mass function, CMF). The IMF and
CMF have been best characterized in the Solar neighborhood. Beyond 500~pc from
the Sun, in diverse environments where metallicity varies and massive star
feedback may dominate, the IMF has been measured only incompletely and
imprecisely, while the CMF has hardly been measured at all. In order to
establish if the IMF and CMF are indeed universal and related to each other, it
is necessary to: 1) perform multi-wavelength large-scale imaging and
spectroscopic surveys of different environments across the Galaxy; 2) require
an angular resolution of < 0.1'' in the optical/near-IR for stars and < 5'' in
the far-IR for cores; 3) achieve far-IR sensitivities to probe 0.1~Msol cores
at 2--3 kpc.
