Published online by Cambridge University Press: 13 January 2023
We first establish a lower bound on the size and spectral radius of a graph G to guarantee that G contains a fractional perfect matching. Then, we determine an upper bound on the distance spectral radius of a graph G to ensure that G has a fractional perfect matching. Furthermore, we construct some extremal graphs to show all the bounds are best possible.
The first author acknowledges the financial support from the National Natural Science Foundation of China (Grant Nos. 12171190, 11671164) and the third author acknowledges the financial support from the National Natural Science Foundation of China (Grant No. 11901179).