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 Apr 25 comment Simplicial homotopy's exponential law Thanks so much for clarifying it! Apr 25 accepted Simplicial homotopy's exponential law Apr 25 asked Simplicial homotopy's exponential law Apr 6 comment Definition of coroots The definition of $\alpha^{\vee}$ is $\frac{(\alpha,\cdot)}{(\alpha,\alpha)}$. Mar 25 awarded Good Answer Mar 9 comment Is it true that $\pi_n(X^{n-1})=0$ for $n>1$ if $X$ is $K(G,1)$ space? Thanks for your answer as well as the one posted in the link. Mar 9 accepted Is it true that $\pi_n(X^{n-1})=0$ for $n>1$ if $X$ is $K(G,1)$ space? Mar 9 asked Is it true that $\pi_n(X^{n-1})=0$ for $n>1$ if $X$ is $K(G,1)$ space? Feb 13 comment What are some topics of advanced number theory every young geometers should know? (soft question) Yes. My PhD subject is non-commutative algebraic geometry, but the field of my interest is rather broader than that. So, I wanted recommendation for general geometers, but then it may be too broad for any suggestion. If my question is not well-posed and therefore doesn't get any answer, I will close it and post a question by trying to make it more well-posed. Feb 13 asked What are some topics of advanced number theory every young geometers should know? (soft question) Jan 24 accepted Why is the sign of $L^2$ opposite? Jan 24 comment Why is the sign of $L^2$ opposite? Great suggestion. I haven't come up with that idea! Jan 24 comment Why is the sign of $L^2$ opposite? I came up with this question, since I thought there would be some convention such that $L^2_x$ is defined as $L^t_xL_x$, which means multiplication of the transposed matrix and the original one. Otherwise the identity doesn't seem to hold. Likewise, if I don't assume the above convention, Casimir element of $\mathcal{so(3)}$ becomes $-\frac{1}{2}(L^2_x+L^2_y+L^2_z)$, which has an incorrect sign. Jan 24 asked Why is the sign of $L^2$ opposite? Jan 23 comment Fubini's theorem for finite dimensional vector space? I didn't think that Haar measure would do the job in that way. Thanks a lot! Jan 22 comment Fubini's theorem for finite dimensional vector space? I'm sorry. I was considering about a Haar measure on $F^n$. It is nice that the standard isomorphism is measure-preserving. While it sounds obvious, I couldn't find it in my textbook. Thank you! Jan 22 asked Fubini's theorem for finite dimensional vector space? Jan 14 comment Calculation of commutator of Lie algebra for affine linear maps It worked pretty good! Jan 14 comment Calculation of commutator of Lie algebra for affine linear maps That makes sense! Thanks a lot. Jan 14 asked Calculation of commutator of Lie algebra for affine linear maps