%0 Report %T Inapproximability proof of DSTLB and USTLB in planar graphs %+ Supélec Sciences des Systèmes (E3S) %+ Centre d'études et de recherche en informatique et communications (CEDRIC) %A Watel, Dimitri %A Weisser, Marc-Antoine %A Bentz, Cédric %Z DIGITEO APPAS %8 2013-02-22 %D 2013 %Z Rapport de recherche %Z Computer Science [cs]/Computational Complexity [cs.CC]Reports %X This document proves the problem of finding a minimum cost Steiner Tree covering k terminals with at most p branching nodes (with outdegree greater than 1), in a directed or an undirected planar graph with n nodes, is hard to approximate within a better ratio than n, even when the parameter p is fixed. %G English %2 https://centralesupelec.hal.science/hal-00793424v1/document %2 https://centralesupelec.hal.science/hal-00793424v1/file/planarcasinapprox.pdf %L hal-00793424 %U https://centralesupelec.hal.science/hal-00793424