Algebra and Number Theory Seminar - Fall 2020
9:30 am, Tuesday, October 6, 2020, Meeting ID: 939 1193 8570, Passcode: 876807
Eran Assaf
Dartmouth College
Computing Equations for Modular Curves
Modular curves are fundamental objects in number theory and lie at the core of several important open problems. We will discuss the state of the art methods for computing their equations, and my attempts to improve them.
9:30 am, Tuesday, October 13, 2020, Meeting ID: 939 1193 8570, Passcode: 876807
Avi Kulkarni
Dartmouth College
Deep learning Gauss-Manin connections
In this talk, I will discuss how machine learning can aid in the computation of the periods of projective hypersurfaces. I will also report on the results of our large-scale computation to find the periods of all smooth quartics in P3 that are the sum of 5 monomial terms with unit coefficients. Joint work with Kathryn Heal and Emre Sertoz.
9:30 am, Tuesday, October 20, 2020, Meeting ID: 939 1193 8570, Passcode: 876807
Carl Mautner
Dartmouth College
Category O for oriented matroids
The representation theory of Lie algebras has rich structure. Recently it was discovered that similar structure can be cooked up from the algebraic geometry of any of a whole zoo of varieties called symplectic resolutions. In joint work with Ethan Kowalenko we produce analogous structure coming from the combinatorics of (oriented) matroids.
9:30 am, Tuesday, October 27, 2020, Meeting ID: 939 1193 8570, Passcode: 876807
Asher Auel
Dartmouth College
Sextic normal genus one curves
I’ll report on progress made with Marcello Bernardara on the problem of showing that every Brauer class is split by a genus one curve. After a brief overview of the problem, I’ll explain our new construction proving the index 6 case, which as a by-product gives a potentially useful presentation of the moduli space of sextic normal elliptic curves.
9:30 am, Tuesday, November 3, 2020, Meeting ID: 939 1193 8570, Passcode: 876807
Jack Petok
Dartmouth College
Modular forms and moduli of hyperkählers
In my thesis and in ongoing work with Jen Berg, we use modular forms to study the birational geometry of some interesting moduli spaces. I'll review a bit of the algebraic geometry of these moduli spaces, and then I'll explain some methods, due to Gritsenko, Hulek, and Sankaran, for computing the Kodaira dimension of these moduli spaces using modular forms defined on high rank orthogonal groIn my thesis and in ongoing work with Jen Berg, we use modular forms to study the birational geometry of some interesting moduli spaces. I'll review a bit of the algebraic geometry of these moduli spaces, and then I'll explain some methods, due to Gritsenko, Hulek, and Sankaran, for computing the Kodaira dimension of these moduli spaces using modular forms defined on high rank orthogonal groups.
9:30 am, Tuesday, November 10, 2020, Meeting ID: 939 1193 8570, Passcode: 876807
Ciaran Schembri
Dartmouth College
Torsion points on abelian surfaces with potential quaternionic multiplication
In a celebrated work Mazur classified which torsion subgroups can occur for elliptic curves defined over the rationals. In this talk I will give a brief introduction to the analogue question of which torsion subgroups can occur for abelian surfaces defined over the rationals which over some extension obtain endomorphisms by an order in a quaternion algebra.
9:30 am, Tuesday, November 17, 2020, Meeting ID: 939 1193 8570, Passcode: 876807
Grant Molnar
Dartmouth College
The LCM Product and Grönwall's Theorem
In this talk, we define the LCM product, due originally to R. D. von Sterneck. We relate the LCM product to Dirichlet convolution, and then prove an analogue to Grönwall's Theorem for kth LCM powers of the identity function on the natural numbers.