Slopes of modular forms


Fredholm series for Up (data and code)

We implement a formula for the characteristic series of Up acting on spaces of overconvergent cuspforms as a two-variable power series over the p-adic integers. We used this implementation to produce the examples in the paper "Arithmetic properties of Fredholm series for p-adic modular forms". A README is included describing those examples. Also included is a pre-computed sage object containing the first 20 (!) coefficients of the characteristic series U2 acting in tame level one.

Code here


Ghost series

Code: The below SAGE code allows one to compute the ghost series, ghost slopes at all weights (even in characteristic p) and to draw pictures of the ghost spectral halo. The top of the code contains a brief explanation of the main functions and how they are used.

SAGE code here

Code: The below SAGE code allows one to compute with abstract ghost series and in particular with ghost series attached to a fixed mod p representation. See the sample run for an explicit example.

Code here

Ghost zeroes vs. true zeros: The below pdf files give tables which compare the location of the true zeroes of coefficients of the Fredholm series of Up to that of the ghost zeroes. From these tables one can see how strikely close the zeroes match. Further, the multiplicity pattern of the ghost zeroes is explained by this data.

p=2 and N=1
p=3 and N=1
p=5 and N=1


Slopes

Click here for a list of the slopes of the Hecke operator T59 acting on cuspforms of level one, in even weights between 2 and 1640.
Compare with the data on Gouvêa's page here.
Click here for this data in a SAGE readable format.
(The format for our file is (k,list) and list is another list containing pairs [a,ma] meaning the slope a appear ma-many times.)

Code: The below MAGMA code allows one to compute the slopes of forms with a fixed residual representation. See the sample run for an explicit example.

MAGMA code here