The Preliminary Arizona Winter School (PAWS) is a virtual program on topics related to the upcoming AWS, with an intended audience of advanced undergraduate students and junior graduate students.
Hamilton famously discovered quaternions in 1843. Today quaternion algebras remain important in many areas of mathematics, from number theory to computer vision, where they offer an efficient framework for calculating rotations. This course will explore some of the structural properties of quaternion algebras and their connections to number theory.
A quaternion algebra is a four-dimensional vector space over a field, endowed with a non-commutative ring structure. Just as the complex numbers extend the real numbers by adjoining an element i (where i2 = -1), quaternion algebras are constructed by adjoining elements i and j to a field whose squares are nonzero elements in the field. Moreover, the elements i,j satisfy the non-commutative relation ij = -ji. We will explore relationships between quaternion algebras, division algebras (where every non-zero element has an inverse), and matrix algebras. Finally, we will examine their connection to solutions of certain quadratic equations.
This course will assume only a first undergraduate course in abstract algebra as a prerequisite, including some knowledge of fields and field extensions.
This course is an introduction to algebraic geometry from a computational point of view. We will study systems of polynomial equations by passing back and forth between their algebra, encoded by ideals in polynomial rings, and their geometry, encoded by the shapes of their solution sets. Along the way, students will learn how computation clarifies geometric questions and how geometric ideas guide effective algebraic or computational methods.
Topics will include affine varieties, polynomial ideals, the correspondence between algebra and geometry, and computational tools such as monomial orders, Gröbner bases, and elimination. The goal is to give a first entry point into algebraic geometry while emphasizing concrete examples, explicit calculations, and the interplay between theory and computation.
Computational algebraic geometry will assume fluency with algebra at a beginning graduate level such as groups, rings, fields and modules, but will not assume any prior knowledge of algebraic geometry.