doctoral_advisor birth_place nationality fields workplaces birth_date article_title name alma_mater
torrence parsons ljubljana , slovenia slovene topological mathematics , configuration -lrb- geometry -rrb- . graph theory , algebraic graph theory , discrete university of primorska , university of ljubljana 24 may 1949 tomaž pisanski
 tomaž pisanski university of ljubljana , pennsylvania state university
tomaž pisanski

tomaž -lrb- tomo -rrb- pisanski -lrb- born may 24 , 1949 in ljubljana , slovenia -rrb- is a slovenian mathematician working mainly in discrete mathematics and graph theory .
in 1980 he calculated the genus of the cartesian product of any pair of connected , bipartite , `` d '' - valent graphs using a method that was later called the `` white -- pisanski method '' .
in 1982 vladimir batagelj and pisanski proved that the cartesian product of a tree and a cycle is hamiltonian if and only if no degree of the tree exceeds the length of the cycle .
they also proposed a conjecture concerning `` cyclic hamiltonicity '' of graphs .
their conjecture was proved in 2005 .
