Resumen:
Let G be a graph of order n and let k ∈ {1, . . . , n−1}. The k-token graph
Fk(G) of G is the graph whose vertices are the k-subsets of V (G), where
two vertices are adjacent in Fk(G) whenever their symmetric difference
is an edge of G. We study the independence and matching numbers of
Fk(G). We present a tight lower bound for the matching number of Fk(G)
for the case in which G has either a perfect matching or an almost perfect
matching. Also, we estimate the independence number for bipartite ktoken
graphs, and determine the exact value for some graphs.