I will show that the groups of mixed 3-manifolds containing
arithmetic hyperbolic pieces and the groups of certain noncompact
arithmetic hyperbolic $n$-manifolds ($n > 3$) are not LERF. The
main ingredient is a study of the set of virtual fibered...
In this talk we will discuss further the existence of knot
complements with essential surfaces of unbounded Euler
characteristics. More precisely, we show the existence of a knot
with an essential tangle decomposition for any number of strings.
We...
I will first describe a simple graph coloring problem and survey
some examples of graphs for which the coloring problem has or has
no solution. I will then give a quick introduction to
Bestvina-Brady Morse theory. Finally, I will describe the...
(Joint with Henry Segerman.) It is a theorem of Moise that every
three-manifold admits a triangulation, and thus infinitely many.
Thus, it can be difficult to learn anything really interesting
about the three-manifold from any given triangulation...
This talk will be about some phenomena that occur as (singular)
hyperbolic structures on 3-manifolds collapse to and transition
through other geometric structures. Typically, the collapsed
structures are much more flexible than the hyperbolic...
