61 research outputs found
Hyperelliptic Theta-Functions and Spectral Methods: KdV and KP solutions
This is the second in a series of papers on the numerical treatment of
hyperelliptic theta-functions with spectral methods. A code for the numerical
evaluation of solutions to the Ernst equation on hyperelliptic surfaces of
genus 2 is extended to arbitrary genus and general position of the branch
points. The use of spectral approximations allows for an efficient calculation
of all characteristic quantities of the Riemann surface with high precision
even in almost degenerate situations as in the solitonic limit where the branch
points coincide pairwise. As an example we consider hyperelliptic solutions to
the Kadomtsev-Petviashvili and the Korteweg-de Vries equation. Tests of the
numerics using identities for periods on the Riemann surface and the
differential equations are performed. It is shown that an accuracy of the order
of machine precision can be achieved.Comment: 16 pages, 8 figure
Nonparabolic subgroups of the modular group
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23916/1/0000160.pd
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