Professor Massimo Lanza de Cristoforis of the University of Padua (Italy) will give a series of five online lectures "Integral operators in Helder spaces on Ahlfors regular sets" for students and postgraduates of mathematical specialties from October 20 to November 17. Lectures will be held on Wednesdays on October 20, 27 and November 3, 10, 17 from 16.30 to 18.00 in English. Participation in the seminar is by appointment only, it is necessary to contact the coordinator Tatyana Mikhailovna Andreeva in advance (before October 19) (tatandreeva@sfedu.ru). Last year, a series of lectures was devoted to the topic "Morey spaces", and the event was organized by the SFedU Regional Scientific and Educational Mathematical Center. The lecture series will be held within the framework of the agreement between the Southern Federal University and the University of Padua, signed in 2019, which provides for joint academic cooperation in educational and scientific activities.