  We investigate a coagulation-fragmentation equation with boundary data,
establishing the well-posedness of the initial value problem when the
coagulation kernels are bounded at zero and showing existence of solutions for
the singular kernels relevant in the applications. We determine the large time
asymptotic behavior of solutions, proving that solutions converge exponentially
fast to zero in the absence of fragmentation and stabilize toward an
equilibrium if the boundary value satisfies a detailed balance condition.
Incidentally, we obtain an improvement in the regularity of solutions by
showing the finiteness of negative moments for positive time.
