Weierstrass p-Function Asympototics?

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Discussion Overview

The discussion centers on the asymptotic behavior of the Weierstrass p-function, specifically examining the expression involving the difference of the function evaluated at two points separated by a period. Participants explore the implications of the function's properties and seek literature that might provide insights into the asymptotics for small and large values of the half-period, ω₁.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant seeks asymptotic information for the Weierstrass p-function as the argument varies, particularly focusing on the behavior for small and large ω₁.
  • Another participant questions the clarity of the variable definitions, specifically whether u is indeed the real part of a complex variable z.
  • A clarification is provided that u is real and ranges from zero to the half-period.
  • Concerns are raised about the original function being identically zero due to periodicity, prompting a correction to the expression involving the Weierstrass p-function.
  • A formula involving Weierstrass Sigma functions is introduced, but the participant expresses concern about the complexity of the infinite product defining the sigma function.
  • Confusion arises regarding the expected behavior of the absolute value of the function, as plots suggest it does not vanish, despite the even nature of the Weierstrass p-function.

Areas of Agreement / Disagreement

Participants do not reach consensus on the behavior of the function or the implications of its properties, with ongoing confusion and questions about the validity of certain expressions and their expected outcomes.

Contextual Notes

There are unresolved assumptions regarding the behavior of the Weierstrass p-function and its relationship to the Weierstrass Sigma function, as well as the implications of periodicity on the expressions discussed.

"pi"mp
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Hi,
I need to study the function:
\bigg| \wp(u ; g_{2}, g_{3})- \wp( (u+2 \omega_{1}); g_{2}, g_{3}) \bigg|

where u is the real part of the argument and I'm using the convention where \omega_{1} is actually half of the overall period on the torus.

Specifically, I'd like asymptotics for both small \omega_{1} and large \omega_{1}. I haven't been able to find anything too helpful in the form of addition formulas or anything.

Has anyone seen anything potentially helpful in any of the literature?
Thanks in advance!
 
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P is a function of a complex variable z. What do you mean that u is the real part of the argument? u = Re(z)? Then the meaning of P(u) is not clear to me. Do you mean you are looking at P(z) only for real values of the argument z?
 
That is indeed what I meant. Sorry. I only care about u real from zero to the half-period.
 
why isn't the function you wrote down identically zero? I.e. you are adding a period to u and hence subtracting the same value.
 
Ugh, you're right...stupid typo I meant to write the function:

\bigg| \wp(u) - \wp(2 \omega_{1} - u) \bigg|

So it vanishes at u=w1 and is indeterminate at u=0. I did find the following formula in terms of Weierstrass Sigma Functions:

\wp(z_{1})-\wp(z_{2}) = \frac{\sigma(z_{1}+z_{2}) \sigma(z_{1}-z_{2})}{\sigma(z_{1})^{2} \sigma(z_{2})^{2}}

however it seems like the infinite product which defines the sigma function will be a pain. Maybe there are asymptotics on the sigma function I can look at.
 
Wait...now I'm confusing myself. The formula with the absolute value that I wrote just above should also vanish right? Since Weierstrass P is even! However, I have plots in mathematica where the absolute value is clearly not zero. I've also made sure that my half-periods agree with my g2, g3 values. What's going on here?
 

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