The mini-course of 9 lectures on differential equations with regular singularities. The themes covered include: Definition of connection and differential equation. Local theory of meromorphic connections with regular singularities. Global theory. Hilbert's 21st problem ( Riemann-Hilbert's problem ), Birkhoff-Grothendieck theorem, Birkhoff standard forms. The course is elementary and will cover some of the material already explained at the Fourier seminar last year. It is aimed at physicists, math students and anybody who missed some of the Fourier seminars and would like to catch up. We loosely follow Bolibrukh's course with the same name, lectures 1-12 in his book "Inverse monodromy problems in analytic theory of differential equations"

The **schedule** is as follows (click for the lecture notes).

April 25.

10:30-12:00 - Lecture 1: Introduction (Todor Milanov)

13:30-15:00 - Lecture 2: Local theory I (Alexander Getmanenko)

16:00-17:30 - Lecture 3: Local theory II (Sergey Galkin)

17:30 discussion

April 26.

10:30-12:00 - Lecture 4: Local theory III (Todor) +exercises

16:00-17:30 - Lecture 5: Global theory (Sergey)

17:30 discussion

April 27.

10:30-12:00 - Lecture 6: Riemann-Hilbert's problem (Sasha)

April 28.

10:30-12:00 - Lecture 7: Birkhoff-Grothendieck's theorem and its corollaries (Todor)

13:30-15:00 - Lecture 8: Another proof of Riemann-Hilbert (Sasha)

16:00-17:30 - Lecture 8.5: Counter-example to Riemann-Hilbert (Sergey)

17:30-18:00 - Lecture 9: Birkhoff standard forms (Sergey)

19:00 afterword, discussion