The Scuola Internazionale Superiore di Studi Avanzati (SISSA) is an international post-graduate-education and research institute (one of the five institute of exellence in italy), founded in 1978 and located in Trieste, Italy. The aim of Junior Math Days is to introduce master students to the research in SISSA (www.sissa.it). We are used to organize the event in the main bulding of the school, in such a way the students can see the city of Trieste and the School, but also to set up a link with the various professors and PhD students that populate the SISSA but, since the recent development to the Covid-19 pandemic, we are forced to organize it by online seminars and meetings via the platform Zoom. The program consists in five days, from the 14th to the 18th of December 2020, of seminars held by the professors and researchers; with the pourpose to introduce the main topics in mathematical research (www.math.sissa.it) , going in geometry, mathematical physics (click HERE for more informations), mathematical analysis and numerical analysis (click HERE for more informations). Apart from the online lectures held by professors, there will be informal online meetings with the PhD students to deepen the academic life.