I have done the following calculation in maple, I want to know if we can do it in Sagemath and write a code using the recursive definition. We construct a family of meromorphic function Wg,n(z1,z2,…,zn). We consturct it recursively. The intial data given is the following.
y(z)=2sinh−1(z/(2a)1/2(z2+2a)1/2 where sinh(z) is sine hyperbolic funciton can be defined directly in maple as it is.
K(z):=1z(y(z)−y(−z))→1/2az2+1/6−z290a+z4378a2−23z628350a3+263z8935550a4−133787z101277025750a5+157009z123831077250a6−16215071z14976924698750a7+2689453969z16389792954801250a8+O(z18) K(z) we define using sinh(z) and take the Taylor series expansion to study the few terms.
Let W0,2(z1,z2):=1/(z1−z2)2
Having this initial data we can construct a tower of Wg,n(z1,z2,…,zn) as follows. Let me give few examples that I have computed by hand in maple.
Let's give some examples of how to generate families of functions W1,1=Resz=0K(z)1z−z1W0,2(z,−z)=1/24z12+3az14 Taking residue at z=0 means collecting the 1/z ceofficients. W0,3(z1,z2,z3)=Resz=0K(z)1z−z1(W0,2(z1,−z)W0,2(z2,z)+W0,2(z2,−z)W0,2(z1,z))=az22z32z12
W1,2(z1,z2)=Resz=0K(z)1z−z1(W0,3(z,−z,z2)+W0,2(z,z2)W1,1(−z)+W0,2(−z,z2)W1,1(z))= 1/8(2az12+5a2)z24+(2az14+3a2z12)z22+5a2z14z16z26 So let's define Wg,n(z1,z2,…,zn) in general by taking the residue of Wg1,n1(z,…)Wg2,n2(−z,…)+Wg−1,n+1() along with the product K(z)1z−z1. Wg1,n1(z1,z2,…,zn1) represent meromorphic functions in n1 variables. And the sum is taken over all such possible combinations. And in case of Wg−1,n+1(z,−z,z2…zn).
In general, if we can write a code where we can give the initial data and then will compute Wg,n(z1,z2,…,zn). It should be a recursive definition. I maple I cannot compute more than (3,1) tuples. But with effective Dynamical programming, we definitely can do more. If someone shows me how to do the initial computation in sagemath, then I will try to write the general programme.