Ok. many thanks for your help! he is the final version:
Hence, I have a genuine interest in pure group-theoretical questions. Moreover, last summer I came across the book "Groups and Symmetry" by M. A. Armstrong. I especially enjoyed reading the chapter that outlined a proof of the Nielsen-Schreier theorem using group actions on trees. Ideas and methods such as these appeal to my attentiveness; that is, problems that are intrinsically discrete, combinatorial. I have read some papers concerning groups of Lie type acting on spherical buildings, and this is a topic I would like to explore in more depth if I have the opportunity. In other words, I am interested in the work of Professor someprof. This is why I'm interested in joining your mathematics department, which seems to have a growing strong group specializing in geometric group theory. Finally, the academic surroundings and atmosphere is another reason why I am considering theuniversity in particular. My objective at the completion of the M.Sc. degree at theuniversity is to continue in research-oriented activities.
