<?xml version="1.0" encoding="UTF-8"?>

<record version="3" id="10589">
 <title>Mellin transform</title>
 <name>MellinTransform</name>
 <created>2008-05-14 18:11:37</created>
 <modified>2008-10-30 08:10:23</modified>
 <type>Definition</type>
 <creator id="6075" name="rspuzio"/>
 <author id="2872" name="pahio"/>
 <author id="6075" name="rspuzio"/>
 <classification>
	<category scheme="msc" code="44A15"/>
 </classification>
 <preamble>% this is the default PlanetMath preamble.  as your knowledge
% of TeX increases, you will probably want to edit this, but
% it should be fine as is for beginners.

% almost certainly you want these
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}

% used for TeXing text within eps files
%\usepackage{psfrag}
% need this for including graphics (\includegraphics)
%\usepackage{graphicx}
% for neatly defining theorems and propositions
%\usepackage{amsthm}
% making logically defined graphics
%\usepackage{xypic}

% there are many more packages, add them here as you need them

% define commands here
</preamble>
 <content>The \emph{Mellin transform} is an integral transform defined as follows:
\[
 F(s) = \int_0^\infty f(t) t^{s-1} \, dt
\]
Intuitively, it may be viewed as a continuous analogue of a power series 
--- instead of synthetizing a function by summing multiples of integer
powers, we integrate over all real powers.  This transform is closely
related to the Laplace transform --- if we make a change of variables
$t = e^{-r}$  and define $g$ by $f(e^{-r}) = g(r)$, then the above integral 
becomes
\[
 F(s) = -\int_{-\infty}^{+\infty} g(r) e^{-rs} \, dr ,
\]
which is a bilateral Laplace transform.

(more to come)</content>
</record>
