PlanetMath (more info)
 Math for the people, by the people. Sponsor PlanetMath
Encyclopedia | Requests | Forums | Docs | Wiki | Random | RSS  
Login
create new user
name:
pass:
forget your password?
Main Menu
Viewing Version 2 of 'linear manifold'
[ view 'linear manifold' | back to history ]

Title of object: linear manifold
Canonical Name: LinearManifold
Type: Definition

Created on: 2003-11-26 14:00:03
Modified on: 2003-11-27 13:33:41

Creator: matte
Modifier: matte
Author: matte

Classification: msc:15-00, msc:15A03
Defines: hyperplane

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

\newcommand{\sR}[0]{\mathbb{R}}
\newcommand{\sC}[0]{\mathbb{C}}
\newcommand{\sN}[0]{\mathbb{N}}
\newcommand{\sZ}[0]{\mathbb{Z}}

% The below lines should work as the command
% \renewcommand{\bibname}{References}
% without creating havoc when rendering an entry in
% the page-image mode.
\makeatletter
\@ifundefined{bibname}{}{\renewcommand{\bibname}{References}}
\makeatother

\newcommand*{\norm}[1]{\lVert #1 \rVert}
\newcommand*{\abs}[1]{| #1 |}
Content:

{\bf Definition} \cite{cristescu} Suppose $V$ is a vector space and suppose that $L$ is a
non-empty subset of $V$. If there exists a $v\in V$ such that $L+v=\{ v+l \mid l\in L\}$
is a vector subspace of $V$, then $L$ is a {\bf linear manifold} of $V$. Then we
say that the dimension of $L$ is the dimension of $L+v$ and write $\dim L = \dim (L+v)$.
If $\dim L = \dim V -1$, then $L$ is called a {\bf hyperplane}.

%\subsubsection{Examples}
A linear manifold is, in other words, a linear subspace that has possibly been
shifted away from the origin.
For instance, in $\sR^2$ examples of linear
manifolds are points, lines (which are hyperplanes), and $\sR^2$ itself.

\begin{thebibliography}{9}
\bibitem{cristescu} R. Cristescu, \emph{Topological vector spaces},
Noordhoff International Publishing, 1977.
\end{thebibliography}