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Angelo Lucia

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Name Angelo Lucia
Member for 1 year
Seen Jun 11 at 17:05
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Location Madrid, Spain
Age 25
PhD student at Universidad Complutense de Madrid.
Apr
9
comment Convolution in $\ell_p$ when $0<p<1$
Just one one: should it be "Fubini", not "Funini"?
Apr
9
comment Convolution in $\ell_p$ when $0<p<1$
Looks like the optimal exponent is exactly max$(p,q)$. To see this, consider two strictly positive sequences: $a_n, b_n >0$. Then trivially $$ a*b(n) = \sum_{k\in \mathbb Z} a_{n-k} b_k \ge a_n b_0 ;$$ and similarly $a*b(n) \ge b_n a_0$. Then $a*b(n)$ cannot go to zero faster than the slower between $a$ and $b$. @Davide: if you want, you should post an answer.
Apr
3
asked Convolution in $\ell_p$ when $0<p<1$