An inequality involving the Dirichlet eta function











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I would be interested in proving the following inequality involving Dirichlet's eta function $eta(s)$ at different values which, after some numerical investigations, I am sure is true



$|chi(1-s)eta(s+2)-eta(3-s)|>0$ $qquad$ $1/2<Re(s)<1$



Here $chi(1-s)=frac{Gamma(s)}{(2pi)^s}2cosleft(frac{pi s}{2} right)frac{1-2^s}{1-2^{1-s}}$ is the factor entering in the functional equation of the Dirichlet eta function



$eta(1-s)=chi(1-s)eta(s)$



Do you have any suggestion on how to attack this problem and/or references that could be helpful? Thank you very much in advance!










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  • You mean: there are no zeros for $Re s > 1/2?$
    – gammatester
    Nov 22 at 18:58










  • Yes. This is exactly what I mean. I have, however, corrected the question, because the region that I have investigated is $1/2<Re{s} < 1$.
    – Frobenius
    Nov 22 at 19:03












  • Ok, I think I have established the result by using that, letting $s=sigma +it$, we have $1/7<|zeta(2+s)/zeta(3-s)|<7$ and $chi(1-s)=O(t^{sigma})$ for sufficiently large $t$. Thanks anyway.
    – Frobenius
    Nov 23 at 14:00

















up vote
0
down vote

favorite












I would be interested in proving the following inequality involving Dirichlet's eta function $eta(s)$ at different values which, after some numerical investigations, I am sure is true



$|chi(1-s)eta(s+2)-eta(3-s)|>0$ $qquad$ $1/2<Re(s)<1$



Here $chi(1-s)=frac{Gamma(s)}{(2pi)^s}2cosleft(frac{pi s}{2} right)frac{1-2^s}{1-2^{1-s}}$ is the factor entering in the functional equation of the Dirichlet eta function



$eta(1-s)=chi(1-s)eta(s)$



Do you have any suggestion on how to attack this problem and/or references that could be helpful? Thank you very much in advance!










share|cite|improve this question
























  • You mean: there are no zeros for $Re s > 1/2?$
    – gammatester
    Nov 22 at 18:58










  • Yes. This is exactly what I mean. I have, however, corrected the question, because the region that I have investigated is $1/2<Re{s} < 1$.
    – Frobenius
    Nov 22 at 19:03












  • Ok, I think I have established the result by using that, letting $s=sigma +it$, we have $1/7<|zeta(2+s)/zeta(3-s)|<7$ and $chi(1-s)=O(t^{sigma})$ for sufficiently large $t$. Thanks anyway.
    – Frobenius
    Nov 23 at 14:00















up vote
0
down vote

favorite









up vote
0
down vote

favorite











I would be interested in proving the following inequality involving Dirichlet's eta function $eta(s)$ at different values which, after some numerical investigations, I am sure is true



$|chi(1-s)eta(s+2)-eta(3-s)|>0$ $qquad$ $1/2<Re(s)<1$



Here $chi(1-s)=frac{Gamma(s)}{(2pi)^s}2cosleft(frac{pi s}{2} right)frac{1-2^s}{1-2^{1-s}}$ is the factor entering in the functional equation of the Dirichlet eta function



$eta(1-s)=chi(1-s)eta(s)$



Do you have any suggestion on how to attack this problem and/or references that could be helpful? Thank you very much in advance!










share|cite|improve this question















I would be interested in proving the following inequality involving Dirichlet's eta function $eta(s)$ at different values which, after some numerical investigations, I am sure is true



$|chi(1-s)eta(s+2)-eta(3-s)|>0$ $qquad$ $1/2<Re(s)<1$



Here $chi(1-s)=frac{Gamma(s)}{(2pi)^s}2cosleft(frac{pi s}{2} right)frac{1-2^s}{1-2^{1-s}}$ is the factor entering in the functional equation of the Dirichlet eta function



$eta(1-s)=chi(1-s)eta(s)$



Do you have any suggestion on how to attack this problem and/or references that could be helpful? Thank you very much in advance!







functional-equations zeta-functions






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 22 at 19:05

























asked Nov 22 at 18:06









Frobenius

613




613












  • You mean: there are no zeros for $Re s > 1/2?$
    – gammatester
    Nov 22 at 18:58










  • Yes. This is exactly what I mean. I have, however, corrected the question, because the region that I have investigated is $1/2<Re{s} < 1$.
    – Frobenius
    Nov 22 at 19:03












  • Ok, I think I have established the result by using that, letting $s=sigma +it$, we have $1/7<|zeta(2+s)/zeta(3-s)|<7$ and $chi(1-s)=O(t^{sigma})$ for sufficiently large $t$. Thanks anyway.
    – Frobenius
    Nov 23 at 14:00




















  • You mean: there are no zeros for $Re s > 1/2?$
    – gammatester
    Nov 22 at 18:58










  • Yes. This is exactly what I mean. I have, however, corrected the question, because the region that I have investigated is $1/2<Re{s} < 1$.
    – Frobenius
    Nov 22 at 19:03












  • Ok, I think I have established the result by using that, letting $s=sigma +it$, we have $1/7<|zeta(2+s)/zeta(3-s)|<7$ and $chi(1-s)=O(t^{sigma})$ for sufficiently large $t$. Thanks anyway.
    – Frobenius
    Nov 23 at 14:00


















You mean: there are no zeros for $Re s > 1/2?$
– gammatester
Nov 22 at 18:58




You mean: there are no zeros for $Re s > 1/2?$
– gammatester
Nov 22 at 18:58












Yes. This is exactly what I mean. I have, however, corrected the question, because the region that I have investigated is $1/2<Re{s} < 1$.
– Frobenius
Nov 22 at 19:03






Yes. This is exactly what I mean. I have, however, corrected the question, because the region that I have investigated is $1/2<Re{s} < 1$.
– Frobenius
Nov 22 at 19:03














Ok, I think I have established the result by using that, letting $s=sigma +it$, we have $1/7<|zeta(2+s)/zeta(3-s)|<7$ and $chi(1-s)=O(t^{sigma})$ for sufficiently large $t$. Thanks anyway.
– Frobenius
Nov 23 at 14:00






Ok, I think I have established the result by using that, letting $s=sigma +it$, we have $1/7<|zeta(2+s)/zeta(3-s)|<7$ and $chi(1-s)=O(t^{sigma})$ for sufficiently large $t$. Thanks anyway.
– Frobenius
Nov 23 at 14:00

















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