Jimmy R
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 Feb 4 asked Do these non-homotopic maps induce the same map in reduced homology? Nov 30 asked Why Do We Associate Quadratic Forms To Symmetric Matrices Rather Than Upper Rriangular Matrices? Oct 26 comment Showing explicitly that a cubic surface is unirational. which term? Originally, a variety $X$ was called birational (over $k$) if there was an invertible map $\mathbb{P}^n_k\dashrightarrow X$ for some $n$ and unirational if the map $\mathbb{P}^n_k\dashrightarrow X$ just goes one way. Then, at some stage, the prefix `bi' got dropped from birational. Oct 25 revised Showing explicitly that a cubic surface is unirational. added 13 characters in body Oct 25 asked Showing explicitly that a cubic surface is unirational. Oct 17 asked Set union in the category of sets Oct 11 accepted $(1-e^{\frac{2\pi i}{n} })(1-e^{\frac{4\pi i}{n} })…(1-e^{\frac{(n-1)2\pi i}{n} })=n$ for each natural $n\geq 2$. Oct 10 accepted Showing that a subset of the complex plane is open. Oct 10 asked Showing that a subset of the complex plane is open. Oct 9 revised $(1-e^{\frac{2\pi i}{n} })(1-e^{\frac{4\pi i}{n} })…(1-e^{\frac{(n-1)2\pi i}{n} })=n$ for each natural $n\geq 2$. edited body Oct 9 reviewed Approve $(1-e^{\frac{2\pi i}{n} })(1-e^{\frac{4\pi i}{n} })…(1-e^{\frac{(n-1)2\pi i}{n} })=n$ for each natural $n\geq 2$. Oct 9 awarded Custodian Oct 9 revised $(1-e^{\frac{2\pi i}{n} })(1-e^{\frac{4\pi i}{n} })…(1-e^{\frac{(n-1)2\pi i}{n} })=n$ for each natural $n\geq 2$. edited body; edited title Oct 9 revised $(1-e^{\frac{2\pi i}{n} })(1-e^{\frac{4\pi i}{n} })…(1-e^{\frac{(n-1)2\pi i}{n} })=n$ for each natural $n\geq 2$. added 1 character in body; edited title Oct 9 comment $(1-e^{\frac{2\pi i}{n} })(1-e^{\frac{4\pi i}{n} })…(1-e^{\frac{(n-1)2\pi i}{n} })=n$ for each natural $n\geq 2$. the statement for $n$ cannot be obtained by simply multiplying the statement for $n-1$ by an additional factor, because all the factors for $n$ and $n-1$ would be different. Oct 9 asked $(1-e^{\frac{2\pi i}{n} })(1-e^{\frac{4\pi i}{n} })…(1-e^{\frac{(n-1)2\pi i}{n} })=n$ for each natural $n\geq 2$. Sep 29 awarded Yearling Sep 21 accepted The existence of a bound for degrees of subsheaves of a coherent sheaf. Sep 21 accepted Does $\operatorname{D}(X)\cong \operatorname{D}(Y)$ imply $X\cong Y$? Sep 21 comment Does $\operatorname{D}(X)\cong \operatorname{D}(Y)$ imply $X\cong Y$? it's very unnatural to talk about isomorphisms of categories even when they are not derived