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Stackings and the W-cycle conjecture

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 نشر من قبل Larsen Louder
 تاريخ النشر 2014
  مجال البحث
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We prove Wises $W$-cycles conjecture. Consider a compact graph $Gamma$ immering into another graph $Gamma$. For any immersed cycle $Lambda:S^1to Gamma$, we consider the map $Lambda$ from the circular components $mathbb{S}$ of the pullback to $Gamma$. Unless $Lambda$ is reducible, the degree of the covering map $mathbb{S}to S^1$ is bounded above by minus the Euler characteristic of $Gamma$. As a consequence, we obtain a homological version of coherence for one-relator groups.



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