April has been a very busy month for me for various reasons. One of them is that I had three preprints put on the arXiv: Let me discuss all of these here with a focus on the first of the three. In each case I try to focus on aspects which are not the focus […]
Traveling China is easy, but a bit tricky for the first. Thus, I give all my visitors a list of instructions. This blog post will summarize my usual advice. It is separated by general advice for China, then a list of useful apps, then specific advice for my university, SUSTech, and Shenzhen. Note that the […]
Addendum (09 April 2025): Several people have told us about a minor mistake in our application of the LLLL. We have an internal version which corrects this. At some point we will correct our preprint on the arXiv. With 7 authors decision making takes some time. Intersecting families and, in particular, the Erdős-Ko-Rado theorem were […]
This is the start of a new category on my blog called “Campus Life”. I will recategorize some of my older posts to it. What is the purpose of my blog? Originally, a grant proposal asked me how I communicate my research to a non-expert audience. Starting a blog seemed like a blog looked like […]
Earlier this year there was a conference in Budapest, Hungary, named Sum(m)it280, to honor the cumulative 280th birthday of the Péter Frankl, Zoltán Füredi, Ervin Győri and János Pach. There the organizers asked participants for survey articles for a conference volume on extremal problems in combinatorics and geometry. Now I have worked a reasonably amount […]
One of the greatest discovery of in the theory of distance-regular graphs has been the twisted Grassmann graph by Edwin van Dam and Jack Koolen. Here I want to describe a small variation of their construction for the twisted $ {D_{5,5}(q)}$ graph. This post mostly to preserve my blackboard on the topic. (I tend to […]
I have uploaded a preprint which concludes a joint work with John Bamberg and Ferdinand Ihringer that started last year during their visit to TU Delft. In this work, we have done one of my favorite things in mathematics research: combining unrelated topics to create something new in each of them. Here is a quick […]
A few days ago China celebrated one of many Chinese Valentine’s days: the 20th of May. Why is this a special day in China? Chinese has around 30 to 36 phonemes which is plenty, but Chinese phonotactics dictate that you can only make around 1200 syllables out of them, for instance, see this video. English […]
