On the genus of the semidirect product o
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Matthew G. Brin; David E. Rauschenberg; Craig C. Squier
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Article
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1989
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John Wiley and Sons
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English
⚖ 632 KB
We show that the non-commutative semidirect product r of Z, by Z, has orientable genus 4. In other words, some Cayley graph of r embeds in an orientable surface of genus 4 (Euler characteristic -61, but no Cayley graph of r embeds in an orientable surface of genus less than 4 (Euler characteristic g