bio | website | |
---|---|---|
location | Moscow | |
age | 24 | |
visits | member for | 4 years |
seen | 6 hours ago | |
stats | profile views | 1,105 |
Nov 21 |
answered | Hartshorne Proposition III 8.1 |
Nov 18 |
awarded | Yearling |
Oct 8 |
comment |
Soft question: beginners reference to moduli spaces
The book is indeed a brother of "Methods of Homological Algebra: Vol. II". Well, we still have drafts and, say, Behrend's lectures mentioned by Piotr. |
Oct 8 |
comment |
Lower semicontinuity of naive fiber size
This is not hard an is a typical Shafarevich-style argument. A tiny improvement to the algebraic counterpart is to state explicitly that given a normal domain $A$ and a finite extension $L$ of its field of fractions $K$ an element $u\in L$ is integral over $A$ iff its minimal polynomial is defined over $A$ (in particular, it exists). Of course, this is essentially Lemma 1. |
Oct 8 |
comment |
About $\mathbb P^1_\mathbb C$ contained in a surface
I'd say that your last paragraph is much more illuminating than doing things explicitly. |
Sep 26 |
answered | Spec of an injective ring map contains minimal primes in its image? |
Sep 26 |
comment |
pencil of quadrics consisting of singular quadrics
@MartinBright As far as I remember, Miles's brilliant thesis deals with the smooth case (allowing only the simplest cones). |
Sep 26 |
answered | pencil of quadrics consisting of singular quadrics |
Aug 27 |
answered | linear section of codimension $k+1$ of a variety of dimension $k$ |
Aug 25 |
comment |
if V(f) is irreducible, then how to show that the polynomial f itself is irreducible?
This is not a research level question. |
Jun 4 |
answered | Why does restriction of Weil divisors “clearly” preserve principal-ness? |
May 15 |
comment |
Reference needed: Homology of the blow-up
Do you put any restrictions on $V$? |
May 14 |
answered | “Exactness” of groupify functor |
Mar 15 |
comment |
Dimension of a commuting nilpotent variety
I'd say that this is a no so trivial question. Namely, if you omit the "commute with $A$" condition, you get the variety of commuting nilpotent matrices. Its dimension is $n^2-1$, which is not obvious (see "The Variety of Pairs of Commuting Nilpotent Matrices is Irreducible" by Volodia Baranovsky). |
Feb 21 |
answered | Easy to state applications of dimension theory in algebraic geometry |
Feb 21 |
answered | Failure of Noether normalization |
Feb 12 |
awarded | Self-Learner |
Feb 11 |
awarded | Revival |
Feb 11 |
awarded | Scholar |
Feb 11 |
accepted | Iterated Pieri's rule, Schur functors and intersection of subrepresentations |