3 ms·
> 1964 > Hironaka solves a major problem concerning the resolution of singularities on an algebraic variety. Essentially, sometimes the varieties (which are g
by mrkgnao 9y ago
> 1964
> Hironaka solves a major problem concerning the resolution of singularities on an algebraic variety.
Essentially, sometimes the varieties (which are geometric objects like curves, surfaces, etc.) studied in algebraic geometry are singular: they might have singularities, like nasty self-crossings or sharp edges. Hironaka's result lets you take a "bad" variety and "resolve its singularities", giving you a good (nonsingular) variety which you can work with instead.
This is in "characteristic zero", i.e. over fields like the real or complex numbers. We also have fields of positive characteristic, e.g. the integers modulo any prime number. Over such fields, I understand that this is a much harder problem to solve.
The aforesaid Heisuke Hironaka is 86 now.
In March of this year, he published a (purported) proof of resolution of singularities in positive characteristic.
The /r/math thread has some good explanations.
https://www.reddit.com/r/math/comments/6aqwbo/hironaka_published_a_proof_of_resolution_of/ https://www.reddit.com/r/math/comments/6aqwbo/hironaka_publi...
- ice109 9y ago>can work with instead what can you actually do with these "smoother" varieties?
- mrkgnao 9y agoThey are much closer to the curves and solids we're familiar with from everyday experience. For example: you have well-defined tangents at every point for a smooth curve, but a self-intersecting curve doesn't. So many techniques and a lot of intuition carries over into the abstract algebraic setting. More generally, algebraic geometry is a central field of math because it is, basically, about solving polynomial equations. It's one of the most "well-connected" fields of mathematics today. Number theory, differential geometry, complex geometry, even differential equations: all these fields benefit from their interactions with modern algebraic geometry. (Also biology, I've heard. Lior Pachter is a name I remember in this connection.)