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How to calculate the integral of a product of a spherical Hankel function with associated Legendre polynomials

From numerical experiments in Mathematica, I have found the following expression for the integral: $$ \int_{-1}^{1}h_{n}^{(1)}\left(\sqrt{a^{2}+b^{2}+2ab\tau}\right)P_{n}^{m}\left(\frac{a\tau+b}{\sqrt{...
Chris's user avatar
  • 31
2 votes
0 answers
245 views

Integral of product of zeroth-order bessel functions times cosine $\int J_{0}\left(\alpha x\right)J_{0}\left(\beta x\right)\cos(kx)\,\mathrm{d}x$

I am new to Bessel functions and need to solve the following integral \begin{equation} \int J_{0}\left(\alpha x\right)J_{0}\left(\beta x\right)\cos(kx)\,\mathrm{d}x \end{equation} with $J_{0}$ ...
Dennis Marx's user avatar
2 votes
0 answers
252 views

Power series of the modified Bessel function of the second kind

I am looking for a power series representation of $$ \frac{1}{K_{\nu}(x)}, $$ where $K_{\nu}$ denotes the modified Bessel function of the second kind and $\nu>-1/2$ is not an integer. I know that ...
esner1994's user avatar
2 votes
0 answers
162 views

Integral rewritten in terms of a modified Bessel function

I am reading this paper by Kunz and Shapiro: they state that the integral (Eqs. 3.17-3.19) $$\int_{-\infty}^\infty\frac{dy}{2\pi}e^{ib(y-i\delta)}\left[\exp\left(-\frac{ia}{y-i\delta}\right)-1\right]\...
baderi's user avatar
  • 21
2 votes
0 answers
571 views

Integrating a product of integrals involving Bessel functions

I have asked similar questions on Math Stack Exchange, but not been able to receive many helpful responses. Therefore, I am posting this problem here, and any input would be extremely valuable. I ...
user363087's user avatar
2 votes
0 answers
194 views

Approximating a divergent integral with modified Bessel functions of the first and second kinds

I am a physicist who needs to evaluate the following (divergent at the origin) integral involving the modified Bessel functions of the first and second kinds $$I = \int_0^{\infty} \frac{\cos(ax)}{x} ...
Nigel1's user avatar
  • 285
2 votes
0 answers
2k views

convolution integral involving modified Bessel functions of the first kind

I'm stuck with this convolution integral ($z \geq 0$)... \begin{equation} f_{Z}(z)=\int^{\infty}_{-\infty}f_{1}(x)f_{2}(z-x)dx = \mbox{ } ??? \end{equation} which represents the pdf of the sum $Z = ...
Gabriele Pompa's user avatar
1 vote
0 answers
81 views

An integral containing modified Bessel functions

During my studies I am facing the following problem. Let $I_\nu(x)$ be the modified Bessel function for $\nu\in(0,1/2]$. I want to compute the following integral (it is are resolvent) $$ R(z) = \frac{...
gdvdv's user avatar
  • 11
1 vote
0 answers
35 views

How to relate this integration with the integral expansion of special functions?

I encounter the following integral when trying to find the inverse Fourier transform of the characteristic function of a certain sum of random variables. Here, $p\ge0$, $q\ge0$ are real, and $n,a,b$ ...
Rekha K.'s user avatar
1 vote
0 answers
71 views

Generalising a one-dimensional integral identity involving Bessel functions to higher dimensions

This was originally posted on Math Stack Exchange, but no responses were received. I recently came across the following remarkable identity, due to Hardy: $$\displaystyle \int_{-\infty}^{\infty} \...
user363087's user avatar
1 vote
0 answers
311 views

Estimating an integral involving Bessel functions

I would like to preface this question by saying that I have asked a series of questions on this topic on Math Stack Exchange, but have almost never received any fruitful responses, with the exception ...
user363087's user avatar
1 vote
0 answers
302 views

Integration involving modified bessel function, exponential and power

I need to find the following integration. $$ \int_0^a e^{-(N-1)x}(\sqrt{4x}K_{1}(\sqrt{4x}))^N $$ where $$ a>0, \quad N \geq 1 $$ Any help will be much appreciated. BR Frank
Frank Moses's user avatar
0 votes
1 answer
397 views

Show integral is positive

Does anyone have any advice or help on how to analytically solve the following problem? Prove that the function $$ \operatorname{f}\left(r\right) = \int_{0}^{\infty}\operatorname{J}_{0}\left(rx\right)\...
Sabiske8's user avatar
0 votes
0 answers
117 views

integral of exponential of Fourier series

I have encountered the following integral: \begin{equation} \int_0^{1} e^{-i F(x)} dx, \quad F(x) = \sum_{k=1}^L a_k \sin(2\pi k x) + b_k \cos(2\pi k x). \end{equation} I have found several great ...
karavan's user avatar
0 votes
0 answers
81 views

Fourier transform of an exponential function with radical argument divided by a radical

I have $f(t)=\dfrac{e^{-i\sqrt{(t-t_0)^2+A^2}}}{\sqrt{(t-t_0)^2+A^2}}$ where $t_0$ and $A$ are constant. I need to take the Fourier transform of $f(t)$. I made few substitutions to take it to a form ...
Ft insat's user avatar
0 votes
0 answers
85 views

Integral of an expression including a fraction having modified Bessel functions of the first kind on both numerator and denominator

I am looking for an analytic result of the following integral $$\iint_0^\infty {{\rm{d}}x{\rm{d}}y{x^2}{y^2}\exp \left\{ { - {\alpha _1}{x^2} - {\alpha _2}{y^2}} \right\}\frac{{{\rm{I}}_1^2\left[ {\...
WeenieHcy's user avatar
0 votes
0 answers
136 views

A complex integration formula

I'm trying to integrate a formula but I can’t figure it out. Its calculation involves an error function. Here's the formula: $f(a, b, c)=\int_{0}^{+\pi} d \theta \exp (a \cos \theta) \operatorname{...
Knight Wang's user avatar
0 votes
0 answers
453 views

Integral involving modified bessel function of second kind, exponential and power

I need to compute the following integral. $$ \int_0^a e^{-bx}\sqrt{4(a-x)}K_1(\sqrt{4(a-x))}dx\,. $$ where $$ a>0$$ and $b$ can be greater than zero or less than zero but it is not a complex ...
Frank Moses's user avatar