  Fast Radio Bursts (FRBs) are a class of highly energetic, mostly
extragalactic radio transients lasting for a few milliseconds. While over 600
FRBs have been published so far, their origins are presently unclear, with some
theories for extragalactic FRBs predicting accompanying high-energy emission.
In this work, we use the Canadian Hydrogen Intensity Mapping Experiment (CHIME)
Fast Radio Burst (CHIME/FRB) Project to explore whether any FRB-like radio
emission coincides in space and time with 81 gamma-ray bursts (GRBs) detected
between 2018 July 17 and 2019 July 8 by Swift/BAT and Fermi/GBM. We do not find
any statistically significant, coincident pairs within 3sigma of each other's
spatial localization regions and within a time difference of up to one week. In
addition to searching for spatial matches between known FRBs and known GRBs, we
use CHIME/FRB to constrain FRB-like radio emission before, at the time of, or
after the reported high-energy emission at the position of 39 GRBs. Our most
constraining radio flux limits in the 400- to 800-MHz band for short gamma-ray
bursts (SGRBs) are <50 Jy at 18.6 ks pre-high-energy emission, and <5 Jy at
28.4 ks post-high-energy emission, assuming a 10-ms radio burst width with each
limit valid for 60 seconds. We use these limits to constrain models that
predict FRB-like prompt radio emission before and after SGRBs. We also place
limits as low as 2 Jy for long gamma-ray bursts (LGRBs), but there are no
strong theoretical predictions for coincident FRB-like radio emission for
LGRBs.
