Abstract:
We consider the equation $F(x)+\Phi(x)=y.$ Here $F: \mathbb{R}^n \to \mathbb{R}^m$ is a nonlinear smooth mapping, $x$ is unknown, $\Phi$ is a continuous mapping, $y$ is a vector. Using $\lambda$-truncations we obtain conditions for the equation to have a solution $x(y,\Phi)$ close to the given point $\bar x$. The perturbation $\Phi$ is assumed to be sufficiently small around $\bar x$ in the uniform convergence metric, and the perturbation $y$ is assumed to be close to $F(\bar x)$. We derive a priori estimates of the solution $x(y,\Phi).$
Keywords:stability of a mapping at a point, inverse function, $\lambda$-truncation.