Here is the PhD Handbook in English (146 Kb) , the Study plan for PhD studies in mathematics (for PhD students who started before 2017-07-01) (104 Kb) and the  Study plan for PhD studies in mathematical statistics, for PhD students who started after 2017-07-01 (380 Kb) , containing course requirements etc.

The following are written in Swedish.

The Faculty of Science has a page (also in Swedish) with useful information for PhD students. See also the handbook for postgraduate students from the Swedish National Agency for Higher Education.