Abstract
In this survey we have attempted to bring together most of the results and papers that deal with toughness related to cycle structure. We begin with a brief introduction and a section on terminology and notation, and then try to organize the work into a few self explanatory categories. These categories are circumference, the disproof of the 2-tough conjecture, factors, special graph classes, computational complexity, and miscellaneous results as they relate to toughness. We complete the survey with some tough open problems!
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Bauer, D., Broersma, H. & Schmeichel, E. Toughness in Graphs – A Survey. Graphs and Combinatorics 22, 1–35 (2006). https://doi.org/10.1007/s00373-006-0649-0
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DOI: https://doi.org/10.1007/s00373-006-0649-0