  We probe the relationship between star formation rate (SFR) and radio
synchrotron luminosity in galaxies at 0 < z < 2 within the northern Spitzer
Wide-area Infrared Extragalactic survey (SWIRE) fields, in order to investigate
some of the assumptions that go into calculating the star formation history of
the Universe from deep radio observations. We present new 610-MHz Giant
Metrewave Radio Telescope (GMRT) observations of the European Large-Area ISO
Survey (ELAIS)-N2 field, and using this data, along with previous GMRT surveys
carried out in the ELAIS-N1 and Lockman Hole regions, we construct a sample of
galaxies which have redshift and SFR information available from the SWIRE
survey. We test whether the local relationship between SFR and radio luminosity
is applicable to z = 2 galaxies, and look for evolution in this relationship
with both redshift and SFR in order to examine whether the physical processes
which lead to synchrotron radiation have remained the same since the peak of
star formation in the Universe. We find that the local calibration between
radio luminosity and star formation can be successfully applied to
radio-selected high-redshift, high-SFR galaxies, although we identify a small
number of sources where this may not be the case; these sources show evidence
for inaccurate estimations of their SFR, but there may also be some
contribution from physical effects such as the recent onset of starburst
activity, or suppression of the radio luminosity within these galaxies.
