The Mathematics Colloquium meets on many Wednesday afternoons during the semester to hear invited lecturers from other universities. All graduate students are encouraged to attend. This is preceded by the Department's large Wednesday afternoon tea, at which there is lively informal discussion as well as cakes for refreshment. On those Wednesdays on which colloquia are not scheduled, there may be special lectures aimed specifically at students. In addition, the Department sponsors the Hans Rademacher Lectures, an endowed series of special lectures that bring mathematicians of world renown to the Department to present important developments in current research. There are two series of Rademacher lectures per year, one each term. The Rademacher Lecturer is in residence for a week, presents four one hour lectures, and is available for informal discussions. During the week of the Rademacher lectures, there are special teas and an especially active social calendar providing ample informal discussion time for faculty, students, and visitors.

There are many weekly seminars at which lecturers, mostly from other institutions, speak about current research. Advanced graduate students are expected to regularly attend at least one of these seminars. There are also a number of student seminars, in which graduate students give the lectures to groups of other students and faculty; reading seminars, in which students and faculty in a given area of mathematics read and discuss recent research papers; and the Pizza Seminar, at which grad students speak to an audience just of other students, and at which the Math Department provides pizza and drinks.

The Department publishes the "Philadelphia Area Mathematical Calendar" weekly, in which all these activities are detailed. There is also a daily afternoon tea at 3 P.M. which is attended by both students and faculty. It provides a valuable informal setting for the regular exchange of ideas.