Monthly Archives: August 2008

Integrable Systems

As part of my project to not let orals actually degrade my sanity beyond recovery, today we’re going to do some physics! Well, kind of. We’ll be citing a lot of physics, at the least, and using it to motivate … Continue reading

Posted in Abelian Varieties, Algebraic Geometry, Curves, Differential Geometry, Mathematical Physics | 2 Comments

Legalities Question

Ok, this might be a silly question, but I’m not sure if something I want to do is legal or illegal. So, I’ve got some books in pdf format that are obtained legally (ie, EGA as downloaded from Numdam) which … Continue reading

Posted in Uncategorized | 3 Comments

Group Schemes and Moduli (II)

We continue our quest to understand when quotients of schemes by actions of group schemes exist. Last time we defined group schemes, group actions, geometric quotients, and gave some examples. In this post, I’ll define what it means to be … Continue reading

Posted in AG From the Beginning, Algebraic Geometry, Examples | 6 Comments

Constructing Nodal Curves

So, I don’t really have a full length post in me at the moment. However, here’s a nice trick that I’ve learned recently, plus some motivation. With this, it’s easy to write down explicitly a curve of arbitrary degree in … Continue reading

Posted in Algebraic Geometry, Curves, Examples | 11 Comments

New Theme

So, we’ve got a new theme. This is for one simple reason: the old one didn’t list the author of posts. This wasn’t an issue before, but today, just before this, is the first post from one of the new … Continue reading

Posted in Uncategorized | 1 Comment

Group Schemes and Moduli (I)

Hi! My name is Matt DeLand, I’m a graduate student at Columbia and I’m responding to Charles’ call for cobloggers. I also study Algebraic Geometry, and have been enjoying Charles’ posts; hopefully I can help out and make some positive … Continue reading

Posted in AG From the Beginning, Algebraic Geometry, Examples | 5 Comments

Request: Projective Elimination Theory

We talked before about elimination theory, doing it entirely in the affine case. The question was asked about how to do it projectively. There are a couple of subtleties to it, but the idea is simple: we eliminate in each … Continue reading

Posted in AG From the Beginning, Algebraic Geometry, Big Theorems, Computational Methods | 2 Comments