Erik Palmgren
Erik Palmgren, professor of mathematical logic at Stockholm University and an eminent researcher in constructive mathematics and categorical logic, passed away unexpectedly in early November 2019 after a short period of ill health.
Erik was born in 1963, near Luleå in northern Sweden.  He studied in Uppsala, where after a masters in computer science, a desire for increased rigour led him to a PhD in mathematical logic under Viggo Stoltenberg-Hansen, completed in 1991.  Aside from short spells in Amsterdam, Munich, and Göteborg, Erik remained at Uppsala until 2011, as research assistant, university lecturer, and finally professor of mathematics.  In 2011 he was recruited to Stockholm as professor, where he was employed until his death.
As a researcher and writer, Erik was thoughtful, reflective, and deliberate. His papers don’t try to tell you in the abstract why to be excited by them; it’s in looking back after reading that you find yourself appreciating their authoritative and insightful treatment of a topic or result.  His research lay generally in the intertwined traditions of constructive mathematics, categorical logic, and type theory.   Specific recurring themes in his work include categorical semantics of type theories; setoid-based mathematics, both concrete applications and big-picture analyses; formal topology; constructive nonstandard analysis; and other topics motivated by constructive-predicativist concerns.
Beyond his own research, Erik devoted great care and energy to teaching, mentoring, and service to the mathematical community.  He was primary supervisor for eight PhD students, and a mentor to many more students and younger researchers in Stockholm, Uppsala, and further afield.  From 2013 to 2015 he was vice-director of the Stockholm Mathematics Centre, besides serving on numerous other scientific committees and editorial boards over the years.  From his arrival in Stockholm in 2011, he gradually built up logic’s presence in the department from a one-man operation to a significant research group.
Personally, Erik was quiet, modest, and much more a listener than talker — not perhaps typical traits in a mathematician.  But his reserved demeanour did little to hide a deep warmth of feeling and care for others: in the appreciations from colleagues after his death, many mentioned how much he had meant not only as a mathematical collaborator, but also as a friend.  Slightly less often on display, perhaps, were his great sense of fun, and his non-mathematical interests, which included Scotch whisky, powerful cars, contrarianism, and doom metal music.
Erik’s death came quite unexpectedly, following what had seemed merely minor health problems.  He had no immediate family; he is mourned by his cousins, friends, and colleagues, in Sweden and around the world.  His passing is a great shock and loss to us all.
His personal website, including publications, can be found at
–Peter LeFanu Lumsdaine,