MINIMAL ELEMENTS IN THE POSET OF GRAPHICAL SEQUENCES

摘要

A noninereasing sequence π of n nonnegative integers graphical is graphical if it is the degree sequence of some simple graph G of order n. All graphical sequences of length n with even sum 2m and trace f forms a poset Gn, m,f under majoriztion relation. In this paper, we characterizc the minimal elememts in Gn, m, f and determine the numbers of minimal elememts in various posers of graphical sequences.