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Viewing Version 10 of 'immanent'
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Title of object: immanent
Canonical Name: Immanent
Type: Definition

Created on: 2003-12-05 17:05:38
Modified on: 2005-05-22 21:16:49

Creator: rspuzio
Modifier: rspuzio
Author: rspuzio
Author: gholmes74

Classification: msc:20C30
Keywords: permanent, determinant, character, trace

Revision comment (for changes between this and next version):

Changes for correction #6684 ('typo').

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
\DeclareMathOperator{\imm}{Imm}
Content:

Let $S_n$ denote the symmetric group on $n$ elements.
Let $\chi:S_n\to\mathbb C$ be a complex character.
For any $n\times n$ matrix $A=(a_{ij})_{i,j=1}^n$ define the \emph{immanent} of $A$ as
\[
\imm_{\chi} (A)=\sum_{\sigma\in {S_n}} \chi(\sigma) \prod_{j=1}^n A(j,\sigma j)
\qquad .\]

Special cases of immanents are determinants and permanents --- in the case where $\chi$ is the constant character ($\chi (x) = 1$ for all $x \in S_n$), $\imm_{\chi} (A)$ is the permanent of $A$. In the case where $\chi$ is the sign pof the permutation (which is the character of the permutation group associated to the one-dimensional representation), $\imm_{\chi} (A)$ is the determinanant of $A$.