Beginners view on resurgence

Perturbative expansions are ubiquitous in physics, often resulting in asymptotic series with zero radius of convergence. In order for the associated observables to become nonperturbatively well-defined one needs to use theory of resurgence.

In this seminar I will give an incomers view on the theory of resurgence functions illustrating basic concepts with simplest examples. Some applications in physics will be shortly reviewed.