P-adic L-functions in universal deformation families

We construct examples of p-adic L-functions over universal deformation spaces for \({{\,\mathrm{GL}\,}}_2\). We formulate a conjecture predicting that the natural parameter spaces for p-adic L-functions and Euler systems are not the usual eigenvarieties (parametrising nearly-ordinary families of automorphic representations), but other, larger spaces depending on a choice of a parabolic subgroup, which we call ‘big parabolic eigenvarieties’.