My research is in the field of algebraic geometry, which studies the
solutions of polynomial equations. I am interested in special systems of
equations which can be characterized geometrically as satisfying a certain
positivity condition (the technical condition is that the anticanonical
class is big). Conjecturally at least, this condition is equivalent to
the arithmetic statement that the corresponding system of equations has
"lots" of solutions in rational numbers (technically you have to be
willing to pass to a larger number field for this statement to be true).
My favorite varieties (the technical term for the space of solutions to a
system of polynomial equations) to study are generalized Del Pezzo
surfaces, which have a rich history dating back to the 19th century. The
most well-known of these surfaces are the cubic surfaces in projective
3-space, given as the zero locus of a single homogeneous cubic polynomial
in four variables. The discovery that these surfaces contain 27 lines was
one of the landmark achievements of algebraic geometry in the 1800s.
These surfaces still hold secrets that have yet to be unlocked.
In many ways, these systems of polynomial equations behaves like
projective space. Projective space can be characterized algebraically
through its graded homogeneous coordinate ring. The varieties I am in
interested, particularly generalized Del Pezzo surfaces, have an analogous
multigraded homogeneous coordinate ring that encodes a lot of geometric
information about the variety. One of my main projects is trying to
understand how to decode all of the information that is contained in this
coordinate ring.
It turns out that the multigrading itself gives information about the
effective cone of the variety. This is a cone which describes what curves
lie on the surface. For generalized Del Pezzo surfaces, this cone turns
out to have a beautifully symmetric structure related to a root system
associated to the surface. Joint work with Zach Teitler and Ulrich
Derenthal has explored some of this symmetry. Ongoing work continues to
apply this beautiful symmetry to conjectures about solutions of the
corresponding system of polynomial equations in rational numbers.