We present results for the volume dependence of baryon number fluctuations in
the vicinity of the (conjectured) critical endpoint of QCD. They are extracted
from the nonperturbative quark propagator that is obtained as a solution to a
set of truncated Dyson-Schwinger equations of (2+1)-flavor QCD in Landau gauge,
which takes the backcoupling of quarks onto the Yang-Mills sector explicitly
into account. This well-studied system predicts a critical endpoint at moderate
temperatures and rather large chemical potential. We investigate this system at
small and intermediate finite, three-dimensional, cubic volumes and study the
resulting impact on baryon number fluctuations and ratios thereof up to fourth
order around the critical endpoint. We find that the fluctuations are visibly
affected by the finite volume, particularly for antiperiodic boundary
conditions, whereas their ratios are practically invariant.Comment: 7 pages, 5 figure