� � � � � � � � � BINGHAMTON GEOMETRY/TOPOLOGY SEMINAR<div class="gmail_quote"><div class="gmail_quote"><div class="gmail_quote"><div>�<br>Date:� Thursday, November 11, 2010<br>Time:� 2:50-3:50pm<br>Place:� Library North 2205 followed by coffee/tea in the Anderson<br>
� � � �� Reading Room.<br>
</div><div class="gmail_quote">�<br>Speaker:� Lucas Sabalka (Binghamton)<br>Title:� Geometry of curve complex analogues for Out(F_n), II<br><br>Abstract:� This is the second of two talks based on our joint work with Dima Savchuk.� One of the most popular open questions about Out(F_n) - a group of outer automorphisms of a free group of rank n - is the construction of a Gromov hyperbolic space on which Out(F_n) naturally acts, extending the deep analogy between Out(F_n), mapping class groups, and linear groups. Each mapping class group naturally acts on a curve complex of the surface, which is hyperbolic due to a celebrated theorem by Masur and Minsky. Many spaces which could serve as an analogue for this space were proposed in recent years.� We will define some of them and concentrate mostly on a space named the ``free factorization graph''. The main outcome of our work is that this space in not hyperbolic, so it should not be considered as an analogue to curve complex.<br>
<br>The second talk will be devoted to further examining the motivation for our definitions, and will discuss some of the results used in our proof.<br></div></div></div>
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