Gregor Bruns
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 Aug 1 revised Interesting type of examples of affine varieties by 'forgetting' polynomial information added 12 characters in body Aug 1 asked Interesting type of examples of affine varieties by 'forgetting' polynomial information Jul 29 comment Is this really a typo? If a function $f$ is $C^k$ for $k\geq 1$ then it automatically is $C^1$, too. So the statement is valid. Jul 4 comment Algebraic Solutions to Systems of Polynomial Equations By 'all variables algebraic' you mean one solution will be a tuple of algebraic numbers? Jun 28 comment An affine open neighborhood of a nonsingular point No, it is not. In fact, it is a rich source of counterexamples regarding schemes that are not varieties. Jun 27 comment An affine open neighborhood of a nonsingular point Your $\Gamma(U,\mathcal{O}_X)$ is (by definition of finite type) a finitely generated $k$-algebra, not just a localization of one. Jun 10 comment My sister absolutely refuses to learn math I tend to agree with your last sentences but it is not at all clear to me whether quick learning later on is not actually also a function of having spent large amounts of time in school on the subject. Jun 3 comment Theorems' names that don't credit the right people Which is not at all wrong since the circumflex just denotes a left-out 's' from old French spelling. May 22 awarded Yearling May 20 awarded Constituent May 7 awarded Caucus Jan 19 awarded Informed Dec 20 comment Find all polynomials that fix $\mathbb Q$ and the irrationals For instance, $x^2$ will map $\sqrt{2}$ to $2$, and therefore be a counterexample. Dec 19 comment Difference between a stalk of a sheaf and a fiber of a vector bundle No need to be sorry. Next to each answer, under the arrows for up/downvoting, there is a little check mark. You can just click on the check mark belonging to the answer you like best to accept it. See here for some images explaining the process. Dec 19 comment Difference between a stalk of a sheaf and a fiber of a vector bundle Please consider accepting some answers to your previous questions. People will be less willing to respond if they think you won't appreciate their answers anyway. Dec 16 comment Normality in a group $G$ Please supply some additional information, so that we can help you better. What have you done? Where are you stuck? Dec 13 suggested rejected edit on Is $R = Q[x] / (x^4 - 3x^2+ 6x)$ isomorphic to a direct sum of two fields? Dec 13 comment Is $R = Q[x] / (x^4 - 3x^2+ 6x)$ isomorphic to a direct sum of two fields? We would appreciate it to see some thoughts of your own on this. Also, it is a bit rude to command us to prove it. Dec 12 comment Let $G_1. …, G_k$ be any groups and $\sigma \in S_k$ a permutation. Prove the following map defines an isomorphism Think about the inverse of the permutation. Dec 11 answered Is the intersection of two quasi-compact open subsets of a scheme quasi-compact?