Blogs about: Ag From The Beginning
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The Weil Pairing
A nice thing about elliptic curves is the wealth of information which is tied up in the isomorphism class of the group. Over the complex numbers, every elliptic curve is where is a lattice of rank 2 c… more →
Rigorous Trivialities
The Weil Pairing
Jim Stankewicz wrote 8 months ago: A nice thing about elliptic curves is the wealth of information which is tied up in the isomorphism … more →
The Dual Isogeny II
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Jim Stankewicz wrote 8 months ago: Apologies that I haven’t been posting recently. Sage days was this past weekend along with 6 i … more →
The Grothendieck Group of Coherent Sheaves on a Variety
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Matt DeLand wrote 9 months ago: Ok, to continue our quest toward the statement of the theorem, we need to explain a few more ideas. … more →
Direct Image Sheaves Under Proper Maps
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Matt DeLand wrote 9 months ago: Today we continue our review/introduction of background material en route to stating and proving the … more →
Proper Maps and (Quasi) Projective Varieties
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Matt DeLand wrote 9 months ago: I’m back! So let’s get down to business. What I really want to talk about is the Rieman … more →
Rational Varieties -- An Introduction Through Quadrics
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Matt DeLand wrote 1 year ago: Projective spaces are the most basic algebraic varieties we know (at least in some sense) and ration … more →
Group Schemes and Moduli (IV)
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Matt DeLand wrote 1 year ago: Unless there is some specific interest, I think this will be the final post in the series about taki … more →
Group Schemes and Moduli (III)
Matt DeLand wrote 1 year ago: Finally we’re ready to discuss what sorts of quotients exist when group schemes act on (some) … more →
Group Schemes and Moduli (II)
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Matt DeLand wrote 1 year ago: We continue our quest to understand when quotients of schemes by actions of group schemes exist. Las … more →
Group Schemes and Moduli (I)
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Matt DeLand wrote 1 year ago: Hi! My name is Matt DeLand, I’m a graduate student at Columbia and I’m responding to Cha … more →
Request: Projective Elimination Theory
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Charles Siegel wrote 1 year ago: We talked before about elimination theory, doing it entirely in the affine case. The question was as … more →
Plücker Formulas
Charles Siegel wrote 1 year ago: Let be a curve and be the dual curve. We say that has traditional singularities if every point of an … more →
Dual Curves
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Charles Siegel wrote 1 year ago: Today we think about plane curves. But first a bit on projective space. Recall that the Grassmannian … more →
Hurwitz's Theorem on Automorphisms
Charles Siegel wrote 1 year ago: This is this blog’s 100th post. Now, not quite my hundredth, nor nearly the hundredth with act … more →
Hurwitz's Theorem
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Charles Siegel wrote 1 year ago: Ok, back to curves. We’d wandered a bit in the direction of this topic before, having discusse … more →
Computing Hilbert Functions
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Charles Siegel wrote 1 year ago: Today, we’ll link the computational thread back to the thread involving Hilbert schemes, by wo … more →
Elimination and Extension Theorems
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Charles Siegel wrote 1 year ago: Last time we talked about Groebner bases and Buchberger’s algorithm, so today we’ll do a … more →
Groebner Bases and Buchberger's Algorithm
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Charles Siegel wrote 1 year ago: After all that technical work and careful but rather abstract technique developed for the constructi … more →
Examples of Moduli Spaces
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Charles Siegel wrote 1 year ago: Now we’re done constructing , so it’s time to get the general Hilbert scheme done, and t … more →
