ON THE CARTAN-HADAMARD CONJECTURE AND THE REGULARITY OF GENERALIZED SURFACES
This thesis brings together the results of two papers developed during the author's doctoral studies, concerning isoperimetric inequalities on manifolds and the regularity of varifolds. These works address distinct questions in geometric analysis and geometric measure theory. The first paper~\cite{agnoletto2026} establishes the generalized Cartan--Hadamard conjecture, also known as the Aubin conjecture, for sufficiently small volumes under a lower Ricci curvature bound, in every dimension greater than or equal to two. It also reduces the proof of the general conjecture to establishing rigidity in the equality case. The second paper~\cite{agnoletto2025allard} establishes Allard's interior $\varepsilon$-regularity theorem in non-collapsed Alexandrov spaces with curvature bounded above and below, and, in particular, in manifolds of class $\mathcal{C}^2$.