Fred Rohrer’s Math Pages

There is no mathematics on a dead planet.

I stopped doing mathematics. I spend now most of my time on politics, post-growth economics, collapsology and the fight against ecological breakdown. I can no longer think about toric schemes or local cohomology whilst knowing that my kids will have to fight wars over food and water.

If you have an urgent mathematical question and think I might know the answer, feel nevertheless free to write me an email (kontakt[at] If I find the time and can remember enough of this stuff, I might try to help you. But: How about joining the fight and write me about that?