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14h
comment John Nash's Mathematical Legacy
@IgorKhavkine: I'm the wrong person to ask.
16h
comment Convergence of a complex series
Please do not answer off-topic questions.
1d
comment John Nash's Mathematical Legacy
@IgorKhavkine: The paper is basically a list of desiderata for a parellel computer.
May
14
comment Second differences of primes determined by increasing first differences: every positive even integer?
@JonMarkPerry: It would really be better if you answered the question.
May
14
comment Second differences of primes determined by increasing first differences: every positive even integer?
@JonMarkPerry: Ah, thanks for clarifying $p_1$ and $p_2$ --- I had indeed missed the fact that these were arbitrary. I'm still not clear on where they're supposed to be ramified.
May
14
comment Second differences of primes determined by increasing first differences: every positive even integer?
@JonMarkPerry ?? Ramified where? And for that matter, what are $p_1$ and $p_2$?
May
12
revised What can I further assume about the speeds of runners of Lonely Runner Conjecture WLOG?
defined notation to render post comprehensible.
May
6
awarded  Excavator
May
6
revised How to recognise that the polynomial method might work
deleted 3 characters in body
Apr
26
comment Google question: In a country in which people only want boys
A tiny correction, years later: In the fourth comment, $(-1)^k$ should be $(-1)^{k+1}$.
Mar
9
comment How to prove that any perfect complex on an affine scheme is strictly perfect?
I might be mistaken, but I'd have thought that the usual definition of "strictly perfect" (as found in, say, SGA6) would replace your "complex of finite rank free sheaves" with a complex of finite rank locally free sheaves. This would rule out Fernando's counterexample.
Mar
9
answered What is $K_2(\mathbb{Z}[x,x^{-1}])$?
Mar
4
comment Communal problem books
Perhaps at least marginally relevant: thebigquestions.com/papers/jimmys.pdf
Mar
3
awarded  Popular Question
Mar
3
awarded  Nice Question
Mar
3
asked Do the real numbers “know” that they are countable in a larger model?
Feb
5
comment map in K-theory
At the level of rings, this is the map $K_n(R)\mapsto K_n(R/I)$ given by taking the class of a projective $R$-module $[P]$ to the class of the (finite projective dimension) $R/I$-module $P/IP$. (Take the alternating sum of the classes of the projective modules occurring in a projective resolution of $P/IP$.) The reason you need smoothness is to insure that $P/IP$ has finite projective dimension so that this class is well defined.
Jan
24
comment Why are they called 'pernicious' numbers?
It looks like Michael Stoll posted while I was typing.
Jan
24
comment Why are they called 'pernicious' numbers?
Let $t(n)$ be the digit sum of the binary representation of $n$. Then Google will tell you that $n$ is called odious if $t(n)$ is odd and evil if $t(n)$ is even. Thus every number is either odious or evil, and therefore the words "odious" and "evil" cannot be pejorative in this context. It seems very likely that "pernicious" was chosen in the same spirit because it starts with the letter "p".
Jan
23
comment Is it possible to create an infinite sequence in which no subsequence is repeated 3 times in a row?
Aside from other issues, the Threefold Repetition Rule described in this post bears very little resemblance to the Threefold Repetition Rule from the actual game of chess.