Rupert McCallum's Website

Welcome to my website. I am a post-doc at the University of Münster.

I am a research mathematician with interests in the theory of building, large cardinals, and geometric group theory.


Publications and preprints

I also take a strong interest in the philosophy of mathematics, physics and its philosophy, normative ethics, and meta-ethics. On previous occasions I gave a talk at the University of Sydney to students about to embark on animal research projects about the philosophy of animal rights. I'm extremely interested in the work Penelope Maddy in the philosophy of set theory and the work of Peter Koellner and Hugh Woodin in set theory and its philosophy. Here is my entry to Sam Harris' Moral Landscape essay competition.

I submitted the following thesis in partial fulfilment for the requirements of my Honours degree in 2003. I was attempting to prove a result about free subgroups of SL(3,k) for an algebraic number field k but only managed to obtain a special case using an argument suggested by my supervisor Professor Michael Cowling. However since that time I have managed to prove a more general result. Tal Poznanski treated this problem in more detail in a PhD thesis of 2008 which I have not been able to find on-line. I have also become aware of related work by G. Soifer and S. Vishkautsan, in Theorem 1.4 of a paper entitled "Simultaneous Ping-Pong Partners in PSL_n(Z)", which includes the special case of my result where the ground field is equal to R.

Here is a draft of a new paper on the philosophy of large cardinals.

Here are some useful resources about effective altruism.


Giving What We Can

Animal Charity Evaluators

Peter Singer's TED talk on effective altruism

Contact me