# Effective theorems in hyperbolic Dehn surgery

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David Futer, Temple University
Fine Hall 314

I will discuss two effective results about hyperbolic Dehn surgery. The first result is about with cosmetic surgery: namely, distinct long Dehn fillings on a cusped manifold cannot yield the same closed 3-manifold. The second result says that long Dehn fillings yield closed 3-manifolds with large Margulis numbers. These results are effective in the sense that all hypotheses and conclusions (such as long'' and large'') are explicitly quantified. This is joint work with Jessica Purcell and Saul Schleimer.