2 papers
math.RA2026
A natural eñe product construction of the Big Witt ring
Daniel Barsky, Ricardo Perez-Marco, Jean-Pierre Ramis
We give a straightforward, self-contained, and natural construction of the Big Witt ring using the eñe product that is defined through the action on zeros of polynomials. This is i…
math.QA2012
The q-analogue of the wild fundamental group and the inverse problem of the Galois theory of q-difference equations
Jean-Pierre Ramis, Jacques Sauloy
In previous papers, we defined -analogues of alien derivations for linear analytic -difference equations with integral slopes and proved a density theorem (in the Galois grou…