activity
20042020
most citedIrreducible Sp-representations and subgroup distortion in the mapping class group

23 citations · 48 across the 8 of their papers we have counts for

collaborators

8 papers

math.GT2020★ 6 cited

The mapping class group of connect sums of

Tara Brendle, Nathan Broaddus, Andrew Putman

Let be the connect sum of copies of . A classical theorem of Laudenbach says that the mapping class group is an extension of $\text{Out}…

math.GT2020

The high-dimensional cohomology of the moduli space of curves with level structures II: punctures and boundary

Tara Brendle, Nathan Broaddus, Andrew Putman

We give two proofs that appropriately defined congruence subgroups of the mapping class group of a surface with punctures/boundary have enormous amounts of rational cohomology in t…

math.GT2013

Finite rigid sets and homologically non-trivial spheres in the curve complex of a surface

Joan Birman, Nathan Broaddus, William Menasco

Aramayona and Leininger have provided a "finite rigid subset" of the curve complex of a surface , characterized by the fact that any si…

math.GT2007★ 15 cited

Homology of the curve complex and the Steinberg module of the mapping class group

Nathan Broaddus

By the work of Harer, the reduced homology of the complex of curves is a fundamental cohomological object associated to all torsion free finite index subgroups of the mapping class…

math.GT2007

Calculating the image of the second Johnson-Morita representation

Joan S. Birman, Tara E. Brendle, Nathan Broaddus

Johnson has defined a surjective homomorphism from the Torelli subgroup of the mapping class group of the surface of genus with one boundary component to , the thir…

math.GT2007★ 3 cited

The Casson invariant and the word metric on the Torelli group

Nathan Broaddus, Benson Farb, Andrew Putman

We bound the value of the Casson invariant of any integral homology 3-sphere by a constant times the distance-squared to the identity, measured in any word metric on the Torell…

math.GT2007★ 23 cited

Irreducible Sp-representations and subgroup distortion in the mapping class group

Nathan Broaddus, Benson Farb, Andrew Putman

We prove that various subgroups of the mapping class group of a surface are at least exponentially distorted. Examples include the Torelli group (answering a question…

math.GT2004★ 1 cited

Noncyclic covers of knot complements

Nathan Broaddus

Hempel has shown that the fundamental groups of knot complements are residually finite. This implies that every nontrivial knot must have a finite-sheeted, noncyclic cover. We give…