7 papers
The platonic elliptic surfaces
Nutsa Gegelia, Duco van Straten
We construct certain special rational elliptic surfaces with four reduced singular fibres that are naturally attached to the platonic solids and belong to a group of surfaces compl…
The Hamiltonian Normal Form
Mauricio Garay, Duco van Straten
An important step in the proof of the Herman invariant tori conjecture was the introduction of a normal form with poles along the resonance loci, replacing the Birkhoff normal form…
Fixed point theorems for small divisors problems
Mauricio Garay, Duco van Straten
In the seventies', Zehnder found a Nash-Moser type implicit function theorem in the analytic set-up. This theorem has found many applications in dynamical systems although its appl…
A new quasi-analytic class
Mauricio Garay, Duco van Straten
Spaces of quasi-analytic classes are defined by the existence and uniqueness of Taylor expansions, which are not necessarily convergent. First examples were given by Borel in his t…
Non degenerate Birkhoff functions
Mauricio Garay, Duco van Straten
It is known after the works of Mahler, Kleinbock, Margulis, Sprindžuk and others that very well approximated numbers on a manifold form a zero measure set, assuming non-degeneracy…
A remarkable eelliptic curve
Duco van Straten
We describe a system of plane algebraic curves defined over \Z, attached naturally to the exponential function. On of these is a remarkable curve of degree 6 that has genus equal t…