Deriving an inequality from a paper

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This discussion revolves around the derivation of inequality (16) from Yann Bugeaud's paper, specifically found on page 13. The participants express difficulty in understanding the derivation, particularly regarding two unresolved questions marked as "how?" on page 12. The conversation highlights the relationship between Lucas pairs and the inequality, suggesting that the left-hand side can be expressed as a power series in α to estimate coefficients. Participants are encouraged to read specific pages of the paper for context and clarity.

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Andrew_99
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Hi, I am studying a paper by Yann Bugeaud:

http://irma.math.unistra.fr/~bugeaud/travaux/ConfMumbaidef.pdf
on page 13 there is an inequality (16) as given below-

attachment.php


which is obtained from -

attachment.php


, on page 12.

How the inequality (16) is derived? I couldn't figure it out. However one of my forum member

tried but it has two problems (problems are marked as "how?"), it is given below-

attachment.php


It is not clear how those two questions would be resolved.

Can anyone show the derivation of inequality (16)?

Thanks in Advance.
 
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Are you missing the latex or images for the equations of interest in your post?

I see gaps but no equations.

POSTSCRIPT: I also had to edit your post to make the link more explicit. We sometimes get posts like this that are actually spam with hidden links.
 
Multiplying it leads to the question whether
$$
\left|\dfrac{\beta^m}{\gamma^n} \cdot \dfrac{\gamma-\delta}{\alpha-\beta}- \dfrac{\delta^n}{\gamma^n} \right| \ll \dfrac{1}{\alpha^{\eta(m-1)}}
$$
given ##\alpha \geq \gamma \geq |\delta|^{1+\eta}\, , \,\alpha \geq |\beta|^{1+\eta}##.

Are there additional relations by the fact that ##(\alpha,\beta)## and ##(\gamma,\delta)## are Lucas pairs?
An idea could be to write the left hand side as a power series in ##\alpha## and estimate the coefficients.
 
jedishrfu said:
Are you missing the latex or images for the equations of interest in your post?

I see gaps but no equations.

POSTSCRIPT: I also had to edit your post to make the link more explicit. We sometimes get posts like this that are actually spam with hidden links.
I used Image from paper.
 
fresh_42 said:
Are there additional relations by the fact that ##(\alpha,\beta)## and ##(\gamma,\delta)## are Lucas pairs?
An idea could be to write the left hand side as a power series in ##\alpha## and estimate the coefficients.
I tried, two other persons tried, see the last image, but failed to get the result, Plz help.
 
Andrew_99 said:
I tried, two other persons tried, see the last image, but failed to get the result, Plz help.
fresh_42 said:
Are there additional relations by the fact that ##(\alpha,\beta)## and ##(\gamma,\delta)## are Lucas pairs?

As far as I can see, there is no restriction on ##\eta## except ##0<\eta <\frac{1}{2}.## Let us assume that ##\eta## is close to zero. Then the assertion is that ##0 \ll \dfrac{\alpha (\gamma - \delta)}{\gamma (\alpha -\beta)} \cdot \dfrac{\alpha^{dr}}{\gamma^{ds}}\ll 2##, i.e. the quotient is close to ##1## in this case. This can be written as ##\alpha^m \gamma +\gamma^n \beta \approx \gamma^n\alpha + \alpha^m \delta##.

As this condition only depends on the given Lucas pairs ##u_m(\alpha,\beta) = v_n(\gamma,\delta)##, I assume that both equations are related; which I don't know since I haven't read the paper. If so, then I would start here and look whether we can go backwards to
$$
\left| \dfrac{\alpha (\gamma - \delta)}{\gamma (\alpha -\beta)} \cdot \dfrac{\alpha^{dr}}{\gamma^{ds}} -1 \right| \ll \alpha^{-\eta rd}
$$
 
fresh_42 said:
As this condition only depends on the given Lucas pairs ##u_m(\alpha,\beta) = v_n(\gamma,\delta)##, I assume that both equations are related; which I don't know since I haven't read the paper.
Read page 12 and 13 (at most, page 10, 11) of below pdf file, for all information required for my query, no need to read the whole paper.
http://irma.math.unistra.fr/~bugeaud/travaux/ConfMumbaidef.pdf

The problem is algebraic derivation which I could not figure out.

You wrote-
fresh_42 said:
the assertion is that ## \dfrac{\alpha (\gamma - \delta)}{\gamma (\alpha -\beta)} \cdot \dfrac{\alpha^{dr}}{\gamma^{ds}}\ll 2##,
do you think
##\alpha^{-\eta rd} \approx 2## ? also please see our attempt in the last image of fist post.
anyway, please inform me if find anything, thanks.
 

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