2 citations · 3 across the 11 of their papers we have counts for
5 papers · 1 filter
The chromatic spectrum of signed graphs
Yingli Kang, Eckhard Steffen
The chromatic number of a signed graph is the smallest number for which there is a function such that $c(v) \not= σ(e) c(…
Circular coloring of signed graphs
Yingli Kang, Eckhard Steffen
Let ( be two positive integers. We generalize the well studied notions of -colorings and of the circular chromatic number to signed graphs. This imp…
The 3-colorability of planar graphs without cycles of length 4, 6 and 9
Yingli Kang, Ligang Jin, Yingqian Wang
In this paper, we prove that planar graphs without cycles of length 4, 6, 9 are 3-colorable.
Choosability in signed planar graphs
Ligang Jin, Yingli Kang, Eckhard Steffen
This paper studies the choosability of signed planar graphs. We prove that every signed planar graph is 5-choosable and that there is a signed planar graph which is not 4-choosable…
Face-degree bounds for planar critical graphs
Ligang Jin, Yingli Kang, Eckhard Steffen
The only remaining case of a well known conjecture of Vizing states that there is no planar graph with maximum degree 6 and edge chromatic number 7. We introduce parameters for pla…