Preserving Regular Tournaments and Term Rank-1
Linear Algebra and its Applications
We investigate linear operators which map certain types of tournaments to themselves. To this end we also characterize term rank-1 preservers on the set of matrices whose associated digraphs are simple loopless directed graphs, and find that this set of operators is more diverse than might be expected.
Beasley, L. B., D.E. Brown and S. Guterman, Preserving Regular Tournaments and Term Rank-1, Linear Algebra and its Applications Issues 5 - 7, (2009) 926 - 936.