The Zero-Divisor Graph Associated to a Semigroup |
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Authors: | Lisa DeMeyer Larisa Greve Arman Sabbaghi Jonathan Wang |
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Affiliation: | 1. Department of Mathematics , Central Michigan University , Mount Pleasant, Michigan, USA demey1la@cmich.edu;3. Department of Mathematics , Wartburg College , Waverly, Iowa, USA;4. Department of Mathematics , Purdue University , West Lafayette, Indiana, USA;5. Department of Mathematics , Harvard University , Cambridge, Massachusetts, USA |
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Abstract: | The zero-divisor graph of a commutative semigroup with zero is the graph whose vertices are the nonzero zero-divisors of the semigroup, with two distinct vertices adjacent if the product of the corresponding elements is zero. New criteria to identify zero-divisor graphs are derived using both graph-theoretic and algebraic methods. We find the lowest bound on the number of edges necessary to guarantee a graph is a zero-divisor graph. In addition, the removal or addition of vertices to a zero-divisor graph is investigated by using equivalence relations and quotient sets. We also prove necessary and sufficient conditions for determining when regular graphs and complete graphs with more than two triangles attached are zero-divisor graphs. Lastly, we classify several graph structures that satisfy all known necessary conditions but are not zero-divisor graphs. |
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Keywords: | Zero-divisor graph Zero-divisor semigroup |
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