Mathematisches Kolloquium

Das allgemeine Kolloquium des mathematischen Instituts findet während der Vorlesungszeit donnerstags um 17:15 Uhr im Hilbertraum (Raum 05-432) statt. Ab 16:45 Uhr gibt es Kaffee und Kuchen.

Vorschau Sommersemester 2024

25.4.
2.5.   Antrittsvorlesung  (16:00 h, Audimax)
Prof. Dr. Hendrik Ranocha (Mainz):
Numerische Mathematik

16.5. Matthias Lesch (Univ. Bonn): title tba
23.5.
6.6.
13.6. Prof. Dr. Frank den Hollander (Univ. Leiden):
The Friendship Paradox for Social Networks

Abstract: In 1991, the American sociologist Scott Feld discovered the paradoxical phenomenon that `your friends are more popular than you are'. This statement means the following. Consider a group of individuals who form a social network. For each individual in the group, compute the difference between the average number of friends of friends and the number of friends (all friendships are mutual), and average these numbers over all the individuals in the group. It turns out that the latter average is always non-negative, and is strictly positive as soon as not all individuals have exactly the same number of friends. This bias, which at first glance seems counterintuitive, goes under the name of friendship paradox, even though it is a hard fact. In this lecture we model the social network as a sparse random graph. We explain where the bias comes from, how it can be quantified, and illustrate our findings with two examples.
Based on joint work with R.S. Hazra and A. Parvaneh.

20.6. Jochen Schütz (Hasselt Univ): title tba
27.6.
4.7.
11.7. Peter Ullrich (Univ. Koblenz): title tba
18.7.

 

>>> Programme früherer Semester (Archiv)