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Jan
18
asked Polynomials representing locally constant functions
Jan
5
reviewed Approve How to cite authors from any country correctly?
Jan
4
comment Uncertainty principle for Mellin transform
To wit: if $f(x)$ decays like $exp(-x^r)$ as $x\to \infty$, then $M(\sigma+i\tau)$ cannot decay as fast as $exp(-c |\tau|)$ for any $c>\pi/2r$. (Well, unless $f$ is $0$ almost everywhere, obviously.)
Jan
4
answered Uncertainty principle for Mellin transform
Dec
12
reviewed Approve Convex hulls of families of probability measures
Dec
12
awarded  Nice Question
Dec
11
asked Non-congruence normal subgroups of $SL_2(\mathbb{Z}[1/2])$
Nov
5
revised Quotients of an extension of the Higman group
added 249 characters in body
Nov
4
revised Quotients of an extension of the Higman group
added 134 characters in body
Nov
3
revised Quotients of an extension of the Higman group
added 174 characters in body
Nov
3
revised Quotients of an extension of the Higman group
added 169 characters in body
Nov
1
revised Normal subgroups of an extension of the Higman group
added 206 characters in body
Oct
31
asked Quotients of an extension of the Higman group
Oct
30
comment Normal subgroups of an extension of the Higman group
Another example to work on (given that I seem to have ungraciously broken yours): what about $atatat^2$? I suspect its closure does contain $H$. Is the same true for every word of the form $a^{k_1} t a^{k_2} t a^{k_3} t^2$?
Oct
30
comment Normal subgroups of an extension of the Higman group
In the last step, don't you get $H/N = \langle a,b|b a b^{-1} = a^2, a b a^{-1} = b^2\rangle$? And isn't that trivial?
Oct
29
revised Normal subgroups of an extension of the Higman group
added 134 characters in body
Oct
26
revised Normal subgroups of an extension of the Higman group
added 373 characters in body
Oct
26
comment Normal subgroups of an extension of the Higman group
Ah, no, I see you do it tacitly at the very beginning. This makes me curious. If we remove the condition $t^4=e$ (but keep the other relations), must the group still be trivial?
Oct
26
comment Normal subgroups of an extension of the Higman group
Thanks! I guess you did not use the condition $t^4=e$ at all to obtain $a=e$?
Oct
24
comment Normal subgroups of an extension of the Higman group
No, I don't think so; conjugate $t^2$ by $a$, say.