# GH

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 Name GH Member for 2 years Seen 20 hours ago Website Location Age
 Jun13 comment Karolyi’s theorem for finite groups and its extensionsRegarding Károlyi's result [1], I heard that Imre Ruzsa found a proof without the Feit-Thompson theorem. Of course I might be wrong, ask either Károlyi or Ruzsa if you are interested. Jun11 revised Karolyi’s theorem for finite groups and its extensionsedited tags Jun7 comment How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sum@Johan: Thank you, I will look at later today. Jun7 comment the following inequality is true，but I can’t prove it@Andres: I think the solution at SE is incorrect. Jun6 comment Does Zhang’s theorem generalize to $3$ or more primes in an interval of fixed length?$k_0=34429$ at the moment Jun6 comment A technical question related to Zhang’s result of bounded prime gapsI changed $\bar{w}$ to $\varpi$ in this post. Jun6 revised A technical question related to Zhang’s result of bounded prime gapsdeleted 8 characters in body Jun6 revised A technical question related to Zhang’s result of bounded prime gapsedited tags Jun6 awarded ● Good Answer Jun6 comment Does Zhang’s theorem generalize to $3$ or more primes in an interval of fixed length?Fresh and relevant: arxiv.org/abs/1306.0948 Jun5 awarded ● Nice Answer Jun4 comment Does Zhang’s theorem generalize to $3$ or more primes in an interval of fixed length?@Noam: Sorry, I had a typo, $\nu-1$ should be $\sqrt{\nu}-1$. For $\nu=1$ the result is the original breakthrough of Goldston-Pintz-Yildirim (very small gaps between primes). Jun4 revised Does Zhang’s theorem generalize to $3$ or more primes in an interval of fixed length?added 7 characters in body Jun4 comment Does Zhang’s theorem generalize to $3$ or more primes in an interval of fixed length?@Noam: I added some information to my response. Jun4 revised Does Zhang’s theorem generalize to $3$ or more primes in an interval of fixed length?added 516 characters in body Jun4 answered Does Zhang’s theorem generalize to $3$ or more primes in an interval of fixed length? Jun4 comment How does this argument to count the cusps of $Γ_0 (N)$ work?I am glad I could help! Jun4 comment How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sum@Johan: There is a typo in your arXiv preprint in the display before (8): $\tau_3(d)$ and $\rho_2(d)$ should be squared as in my response below. Thanks for the footnote. Jun4 comment How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sum@Johan: There is a typo in your arXiv preprint in the display before (8): $\tau_3(d)$ and $\rho_2(d)$ should be squared as in my response below. Thanks for the footnote. Jun4 accepted How does this argument to count the cusps of $Γ_0 (N)$ work? Jun4 revised Show that this ratio of factorials is always an integeredited tags Jun1 comment A question on Haar measure on local field.Yes, but this is not what you originally asked. Your question involved $F^{\times 2}$ as a subset of $F^\times$ (not just as an abstract group), hence the correction factor you need (in your original equation) will also depend on the index $(F^\times:F^{\times 2})$. This, on the other hand, depends on whether $2$ is a unit in the maximal compact subring of $F$ or not. Read my response. Jun1 answered How does this argument to count the cusps of $Γ_0 (N)$ work? Jun1 revised A question on Haar measure on local field.deleted 108 characters in body Jun1 comment A question on Haar measure on local field.@paul: Yes, the discrepancy is a uniform constant. And my response was also slightly in error, so let me update it. Jun1 revised A question on Haar measure on local field.deleted 1 characters in body Jun1 answered A question on Haar measure on local field. Jun1 accepted determining sign of function containing logarithm. Jun1 revised determining sign of function containing logarithm.added 218 characters in body Jun1 comment determining sign of function containing logarithm.I answered your clarified question below. For any $m>e^e$ there is $m_0>m$ such that $f(m,n)<0$ for any $n\in(m,m_0)$. Jun1 comment determining sign of function containing logarithm.@asd: I have now answered your clarified question. Jun1 revised determining sign of function containing logarithm.added 187 characters in body; added 19 characters in body Jun1 revised determining sign of function containing logarithm.added 185 characters in body Jun1 answered determining sign of function containing logarithm. Jun1 comment How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sum@i707107: Got it, thanks! Jun1 accepted How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sum Jun1 comment How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sumThe method I outlined gives C-S precisely (note the factor 2 on the left). Jun1 awarded ● Nice Answer May31 comment How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sumThis is nice, but I think that secretly you reproduced the proof of Cauchy-Schwarz. At least one proof goes like this: $2\sum x_iy_i\leq\sum (x_i^2k^{-2}+y_i^2k^2)$. Minimmizing the right hand side in $k$ yields Cauchy-Schwarz. May31 revised How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sumedited body May31 revised How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sumadded 2 characters in body May31 comment How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sumSee also the postscript in my response. Good luck to your talk! May31 comment How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sumI agree. I think Zhang understood several years ago that this estimate was the one to focus on, and later he did not bother or forgot to explain it so well. May31 answered How does Yitang Zhang use Cauchy’s inequality and Theorem 2 to obtain the error term coming from the $S_2$ sum May30 answered An estimate of an integral May30 revised An estimate of an integral edited body; edited tags May24 awarded ● Good Question May24 awarded ● Notable Question May24 awarded ● Popular Question May24 awarded ● Nice Question