Computational Algebra Seminar: Yasaki, Wilson

Speaker: Dan Yasaki
Title: Hecke operators and Bianchi forms
Time & Place: 3-4pm, Thursday 14 May, Carslaw 535.

Abstract:  The eigenvalues of Hecke operators give rise to arithmetically
interesting data.  This talk will begin with a brief overview of one
approach to computing Hecke operators on classical modular forms, but
phrased in terms of Voronoi polyhedra and sharblies.  I will describe some
of the complications that arise when the change is made from the rational
numbers to a number field.  Then I will specialize to imaginary quadratic
fields, giving a brief demonstration in Magma.

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Coffee & Cake Break
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Speaker: Rob Wilson
Title: A New Approach to the Leech Lattice
Time & Place: 4-5pm, Thursday 14 May, Carslaw 535.

Abstract: The Leech lattice is a remarkable object with many applications in
group theory, number theory, coding theory and elsewhere.  It lives in
24-dimensional space, and its many constructions are all rather technical.
I outline a new approach which uses octonions to avoid many of the
difficulties.