Astro2020 Science White Paper: The Formation and Evolution of Multiple
  Star Systems
  Significant advances have been made over the past decade in the
characterization of multiple protostar systems, enabled by the Karl G. Jansky
Very Large Array (VLA), high-resolution infrared observations with the Hubble
Space Telescope, and ground-based facilities. To further understand the
mechanism(s) of multiple star formation, a combination of statistics,
high-angular resolution radio/millimeter continuum imaging, characterization of
kinematic structure, magnetic fields via polarimetry, and comparison with
numerical simulations are needed. Thus, understanding the origin of stellar
multiplicity in different regimes of companion separation will soon be within
reach. However, to overcome challenges that studies in this field are now
confronted with, a range of new capabilities are required: a new
millimeter/centimeter wave facility with 10 mas resolution at {\lambda}=1 cm,
space-based near to far-infrared observatories, continued development of low to
high resolution spectroscopy on 3m to 10m class telescopes, and an ELT-class
telescope with near to mid-infrared imaging/spectroscopic capability.
