On Tue, May 26, 2020 at 9:35 AM Preston Wake <[email protected]> wrote: > Does anyone know what ModularSymbols(G,k,base_ring=R) is computing? Is maybe > it ismort, where subscript-G means coinvariants?
It uses a characteristic 0 presentation involving Manin symbols, but does the linear algebra over R instead of QQ. If you know enough about a situation (e.g., you are interesting in p=5 say and the dimension is the same) then this can be extremely efficient and useful. But for some small values of p, e.g., p=2 or 3, you can end up with an object that is basically useless (e.g., "Hecke operators" on it don't commute). Kevin Buzzard and I once worried about this problem when writing [1] (see Remark 1.2 on page 268). -- William [1] https://wstein.org/papers/artin/buzzard-stein.pdf -- William (http://wstein.org) -- You received this message because you are subscribed to the Google Groups "sage-nt" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-nt/CACLE5GC%2B2kbn57tTmPg4XUwP%2Bm2_RR1xW0W-AjjXXWkbfWXvSQ%40mail.gmail.com.
