3 papers
math.AP2026
Stationary points of conformally invariant polyconvex energies
André Guerra, Riccardo Tione
We consider polyconvex integrands that are conformally invariant and frame indifferent. In two dimensions, we prove that the corresponding stationary points are smooth outside a di…
math.AP2026
Some lifting and approximation properties for maps in
André Guerra, Xavier Lamy, Konstantinos Zemas
Smooth maps can be lifted to using the Hopf fibration via the factori…
math.AP2025
Constancy of the index for gradient mappings
André Guerra, Riccardo Tione
We show that if the Hessian of a function has uniformly positive determinant almost everywhere then its index is locally constant, as conjectured by Å verák in 1992. We…