I will discuss recent progress in the analytic study of classical partition identities, including the famous « sum-product » formulas of Rogers-Ramanujan, Schur, and Capparelli. Such identities are rich in automorphic objects such as Jacobi theta functions, mock theta functions, and false theta functions. Furthermore, there are interesting connections to the combinatorics of multi-colored partitions, and the calculation of standard modules for Lie algebras and vertex operator theory.[-]

Let $k > 2$ be a real number. We inquire into the following question : what is the maximal size (inner Lebesque measure) and the form of a set avoiding solutions to the linear equation $x + y = kz$ ? This problem was used for $k$ an integer larger than 4 to guess the density and the form of a corresponding maximal set of positive integers less than $N$. Nevertheless, in the case $k = 3$, the discrete and the continuous setting happen to be very different. Although the structure of maximal sets in the continuous setting is quite easy to describe for $k$ far enough from 2, it is more difficult to handle as $k$ comes closer to 2. Joint work with Alain Plagne.[-]