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location Moscow
age 24
visits member for 3 years, 11 months
seen Oct 15 at 15:14

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
Feb
11
answered Iterated Pieri's rule, Schur functors and intersection of subrepresentations
Feb
11
asked Equivariant derived category and invariant divisor