For the special class of so-called double partition s, Gomez-Ullate, Grandati and Milson showed that the corresponding polynomi als are orthogonal and dense in the space of all polynomials with respect t o a certain inner product, but in contrast to their classical counterparts have some degrees missing (so-called exceptional orthogonal polynomials). I will describe how their results can be generalised to all partitions by us ing the notion of quasi-invariance and considering complex contours of inte gration and non-positive, but Hermitian, inner products.

If time p ermits, I will also indicate a multivariate generalisation of some of these results. The talk is based on joint work with W.A. Haese-Hill and A.P. Ves elov. DTSTAMP:20201126T025041Z DTSTART;TZID=Europe/Budapest:20180508T100000 DTEND;TZID=Europe/Budapest:20180508T110000 SEQUENCE:0 TRANSP:OPAQUE END:VEVENT END:VCALENDAR