# Mathematics

During my last year at the Gymnasium, one of high school’s German relatives, I had to decide on what to study. I was interested in mathematics, physics, and computer science. Mathematics and physics where my favorite classes and, by then, I had been teaching myself to code for close to nine years.

Physics was quickly eliminated from my list, though I no longer remember why. That left mathematics and computer science. In my youthful naïveté, I thought that I could teach myself everything interesting computer science had to offer, and thus decided on studying mathematics. Even though the rationale was questionable, it was the right choice. On the one hand, I enjoyed studying mathematics and it came to me naturally—the latter probably causing the former. On the other hand, of course, I did not teach myself everything interesting I might have learned studying for a computer science degree. In any case, my practical software development experience was enough for me to land an interesting job right after finishing with my PhD studies.

I started to study mathematics in Ilmenau where I got my Diplom, the mostly discontinued German cousin of a Master’s degree.

Right from the start, I was looking for a way to study abroad. I thought aiming high would not hurt and applied to the University of Cambridge after my second year. My boldness payed off and I spent a year doing Part III as a member of Magdalene College. This got me a Master’s degree, even before finishing my degree at the German university.

With two degrees under my belt, I started to work towards a PhD. At first in Ilmenau, then continuing in Ulm, following my supervisor when he accepted a new position. At the end of 2012, I was done. The field of research of my doctoral thesis can be categorized as a mixture of graph theory and discrete algorithms.

I end this page with a list of mathematical publications that I coauthored. Thanks to a publication that I coauthored with Vašek Chvátal, I have Erdős number 2—the lowest I could reasonably get, given that Erdős died when I was 10.

Dieter Rautenbach, Vinícius Fernandes dos Santos, and Philipp Matthias Schäfer

Irreversible Conversion Processes with Deadlines

Journal of Discrete Algorithms,

**26**, 69-76, 2014Dieter Rautenbach, Philipp Matthias Schäfer

Null-Homotopic Graphs and Triangle-Completions of Spanning Trees

UTILITIAS MATHEMATICA,

**92**, 359-363, 2013Michael A. Henning, Dieter Rautenbach, and Philipp Matthias Schäfer

Open Packing, Total Domination, and the P₃-Radon Number

Discrete Mathematics,

**313**, 9, 992-998, 2013Mitre Costa Dourado, Dieter Rautenbach, Vinícius Fernandes dos Santos, Philipp Matthias Schäfer, and Jaime Luiz Szwarcfiter

On the Carathéodory Number of Interval and Graph Convexities

Theoretical Computer Science,

**510**, 127-135, 2013Mitre Costa Dourado, Dieter Rautenbach, Vinícius Fernandes dos Santos, Philipp Matthias Schäfer, Jaime Luiz Szwarcfiter, and Alexandre Toman

An Upper Bound on the P₃-Radon Number

Discrete Mathematics,

**312**, 16, 2433-2437, 2012Mitre Costa Dourado, Dieter Rautenbach, Vinícius Fernandes dos Santos, Philipp Matthias Schäfer, Jaime Luiz Szwarcfiter, Alexandre Toman

On the Radon Number for P₃-Convexity

LATIN 2012: Theoretical Informatics, Lecture Notes in Computer Science, Springer,

**7256**, 267-278, 2012Dieter Rautenbach and Philipp Matthias Schäfer

Strict Betweenness Induced by Posets as well as Graphs

Order,

**28**, 1, 89-97, 2011Dieter Rautenbach, Vinícius Fernandes dos Santos, Philipp Matthias Schäfer, and Jaime Luiz Szwarcfiter

On Subbetweennesses of Trees: Hardness, Algorithms, and Characterization

Computers & Mathematics with Applications,

**62**, 12, 4674-4681, 2011Dieter Rautenbach, Vinícius Fernandes dos Santos, Philipp Matthias Schäfer, and Jaime Luiz Szwarcfiter

Characterization and Representation Problems for Intersection Betweenness

Discrete Applied Mathematics,

**159**, 5, 389-395, 2011Mitre Costa Dourado, Dieter Rautenbach, and Philipp Matthias Schäfer

On Finite Convexity Spaces Induced by Sets of Paths in Graphs

Discrete Mathematics,

**311**, 8-9, 616-619, 2011Vašek Chvátal, Dieter Rautenbach, and Philipp Matthias Schäfer

Finite Sholander Trees, Trees, and their Betweenness

Discrete Mathematics,

**311**, 20, 2143-2147, 2011