Abstract:
We study the solubility of systems of non-linear equations in a neighbourhood
of an abnormal point and prove inverse function theorems that guarantee
the existence of solutions satisfying a linear-root estimate in the
neighbourhood of the abnormal point. We also address the related issue
of necessary conditions for an extremum at an abnormal point
in a finite-dimensional constrained problem. We obtain second-order necessary
optimality conditions that improve the known results.
Keywords:inverse function theorem, abnormal point, conditional extremum problem.