Eugene Stepanov (Univ. San Pietroburgo) ``Transportation of measures through branched networks at finite cost'' ABSTRACT: The following transportation problem is studied: characterize those couples of finite Borel measures with compact supports in a Euclidean space that can be transported to each other at a finite fractional cost, given by a fractional mass of real one-dimensional normal currents. Besides the class of irrigable measures (i.e. measures which can be transported to a Dirac measure with the appropriate total mass at a finite cost), two other important classes of measures related to the problem are studied which in a certain sense are complementary to each other.