Deforming regular black holes
  In this work we have deformed regular black holes which possess a general
mass term described by a function which generalizes the Bardeen and Hayward
mass functions. By using linear constraints in the energy-momentum tensor to
generate metrics, the solutions presented in this work are either regular or
singular. That is, within this approach, it is possible to generate regular or
singular black holes from regular or singular black holes. Moreover, contrary
to the Bardeen and Hayward regular solutions, the deformed regular black holes
may violate the weak energy condition despite the presence of the spherical
symmetry. Some comments on accretion of deformed black holes in cosmological
scenarios are made.
