6 DIMENSION OF THE TORELLI GROUP FOR Out ( F n )
نویسنده
چکیده
Let Tn be the kernel of the natural map Out(Fn) → GLn(Z). We use combinatorial Morse theory to prove that Tn has an Eilenberg–MacLane space which is (2n − 4)-dimensional and that H2n−4(Tn, Z) is not finitely generated (n ≥ 3). In particular, this recovers the result of Krstić–McCool that T3 is not finitely presented. We also give a new proof of the fact, due to Magnus, that Tn is finitely generated.
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تاریخ انتشار 2008