I Hypergeometric Limits: Analyzing p(x)

thatboi
Messages
130
Reaction score
20
I have been working with some Hypergeometric functions whose behavior I am not quite familiar with. Suppose the equation I wish to analyze is
##p(x) = (e^{x}-1)^{2i}\left({}_{2}F_{1}(a,b;c;e^{x}) + {}_{2}F_{1}(a+1,b+1;c+1;e^{x})\right)## where ##a,b,c## are all complex valued and we have ##\Re(c-a-b)>0## and we have ##\Re((c+1)-(a+1)-(b+1))=0## but ##(a+1)+(b+1)-(c+1) = 2i##. My question is, how do I take the proper limit of ##p(x)## as ##x\rightarrow 0##. I believe the relevant identities are (15.4.20) and (15.4.22) from https://dlmf.nist.gov/15.4 but there is still the limit of figuring out what ##0^{i}## means.
Let me know if you guys have any ideas. Thanks!
 
Physics news on Phys.org
(e^x-1)^{2i}=e^{2\log(e^x-1)i}
So as x##\rightarrow## 0, phase becomes undermined.
 
There is the following linear Volterra equation of the second kind $$ y(x)+\int_{0}^{x} K(x-s) y(s)\,{\rm d}s = 1 $$ with kernel $$ K(x-s) = 1 - 4 \sum_{n=1}^{\infty} \dfrac{1}{\lambda_n^2} e^{-\beta \lambda_n^2 (x-s)} $$ where $y(0)=1$, $\beta>0$ and $\lambda_n$ is the $n$-th positive root of the equation $J_0(x)=0$ (here $n$ is a natural number that numbers these positive roots in the order of increasing their values), $J_0(x)$ is the Bessel function of the first kind of zero order. I...
Back
Top