I’m having one of those things… A headache with pictures…
So I looked into it and Topology and sigma-algebra are distinct things. Apparently a sigma-algebra need only be closed under countable intersection, whereas a topology requires arbitrary intersections to be included. Also topologies won’t necessarily be closed under complement, whereas sigma-algebras will be. But the smallest sigma-algebra containing some topolgy is called the “Borel sigma-algebra.” So that’s that all cleared up…
I took out a book on Euclidean geometry today written by none other than Charles L. Dodgson; better known as Lewis Carroll. Cool huh? And what is more, it’s written as a dialogue! I also recently managed to find Alfred Renyi’s Dialogues on Mathematics. So I’m pleased with both of them.
What with various talks and my being quite lazy I haven’t really managed to get a whole lot done today. And I’m to a conference tomorrow. So this week has been a bit of a write-off really. The real proper work on my dissertation kicks off on Monday. Hoorah!