Chung Lok Andrew Ng

Hi! My full name is Chung Lok Andrew Ng, but I usually just go by Andrew unless I’m trying to avoid getting confused with an AI scientist. I am a second year PhD student at the University of Bonn working in geometric group theory. My current interests are group rings of infinite groups and groups acting on rooted trees. You can contact me at clan [at] math.uni-bonn.de.

Preprints

1. Virtual First Betti Number of GGS Groups.

Other Writing
Various extracurricular mathematics opportunities are available to students at the University of Cambridge, including competitions for exposition. My entries can be found below. I apologise in advance for any errors.

• I did a summer research project on random groups under the supervision of Calum Ashcroft. The report can be found here. Note that better results have been obtained.
• Lagrange’s 4-squares theorem
• Bass-Serre theory
• Combinatorial Morse Theory
• CAT(0) cube complexes

Organisation
I have organised the following reading groups at Bonn:

1. Bounded cohomology SS (Sommersemester) 24.
2. Buildings WS (Wintersemester) 24/25.
3. JSJ decompositions SS 25. The notes for this are available on this blog.

Teaching
I was a TA for the course Einführung in die Geometrie und Topologie in SS 24.

Outreach
I have helped mark mathematics Olympiads for secondary school students at a national and international level. I was on the Problem Selection Committee for IMO 2024. Over the past years I have taught at the annual maths camp organised by UKMT at Trinity College, Cambridge. The teaching material I used for this is available upon request. I have also been a guest writer for this blog on Olympiad mathematics.

Other

• The most fun maths and art crossover I have ever seen has to be the widget on Jonathan Fruchter’s homepage.
• While a student at Cambridge I helped make knotted dumplings. Photos can be found here, although Gheehyun’s later experiments have been much more elaborate.