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Register a new userThe automorphism group of the universal Coxeter group
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Authors
Olga Varghese
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We study fixed point properties of the automorphism group of the universal Coxeter group Aut$(W_n)$. In particular, we prove that whenever Aut$(W_n)$ acts by isometries on complete $d$-dimensional CAT$(0)$ space with $d<lfloorfrac{n}{2}rfloor$, then it must fix a point. We also prove that Aut$(W_n)$ does not have Kazhdans property (T). Further, strong restrictions are obtained on homomorphisms of Aut$(W_n)$ to groups that do not contain a copy of Sym(n).
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