  The experimental observation of neutrino oscillations profoundly impacted the
physics of neutrinos, from being well understood theoretically to requiring new
physics beyond the standard model of particle physics. Indeed, the mystery of
neutrino masses implies the presence of new particles never observed before,
often called sterile neutrinos, as they would not undergo standard weak
interactions. And while neutrino oscillation measurements entered the precision
era, reaching percent-level precision, many experimental results show
significant discrepancies with the standard model, at baselines much shorter
than typical oscillation baselines, like LSND, MiniBooNE, gallium experiments,
and reactor antineutrino measurements. These short baseline anomalies could be
explained by the addition of a light sterile neutrino, with mass in the
$1-10~\text{eV}$ range, however, in strong tension with many null experimental
observations. Other explanations that rely on sterile neutrinos with masses in
the $1-500~\text{MeV}$ could resolve the tension. Here we test both classes of
models. On the one hand, we look for datasets collected at a short baseline
which can constrain heavy sterile neutrino models. We find that the minimal
model is fully constrained, but several extensions of this model could weaken
the current constraint and be tested with current and future datasets. On the
other hand, we test the presence of neutrino oscillations at short baselines,
induced by a light sterile state, with the data collected by the MicroBooNE
experiment, a liquid argon time projection chamber specifically designed to
resolve the details of each neutrino interaction. We report null results from
both analyses, further constraining the space of possible explanations for the
short baseline anomalies. If new physics lies behind the short baseline anomaly
puzzle, it is definitely not described by a simple model.
