76th Annual Meeting of the Southeastern Section of APS
Volume 54, Number 16
Wednesday–Saturday, November 11–14, 2009;
Atlanta, Georgia
Session CD: Mathematical Methods
10:45 AM–12:33 PM,
Thursday, November 12, 2009
Room: Brussels
Chair: Toan Nguyen, Georgia Institute of Technology
Abstract ID: BAPS.2009.SES.CD.9
Abstract: CD.00009 : Generating Geometrical Elements for Any Space-Time
12:21 PM–12:33 PM
Preview Abstract
Abstract
Author:
Dennis Marks
(Valdosta State U.)
To distinguish time from space, use real Clifford algebras $\bf
{R}$$_{n;s}$, where $n$ is the number of dimensions and $s$ is
their signature ($s=-n, -n+2, {\ldots}$, or $n$). $\bf{R}$$_
{n;s}$ is isomorphic to algebras of real, complex, or
quaternionic matrices ${\rm {\bf R}}(2^{\textstyle{n \over {\rm
{\bf 2}}}})$, ${\rm {\bf C}}(2^{\textstyle{{n-1} \over 2}})$,
or ${\rm {\bf H}}(2^{\textstyle{{n-2} \over 2}})$, or of block
diagonal matrices ${ }^2{\rm {\bf R}}(2^{\textstyle{{n-1} \over
2}})\mbox{ }$ or ${ }^2{\rm {\bf H}}(2^{\textstyle{{n-3} \over
2}})\mbox{ }$, for $\vert (s~$+~3)$_{mod8}$~-~4$\vert $ = 1, 2,
3, 0, or 4, respectively. Each of the $n$ basis vectors $\bf{e}
$$_{\nu}$ satisfies ${\rm {\bf e}}_\mu {\bf{\cdot}}~ {\rm {\bf
e}}_\nu =\eta _{\mu \nu } {\rm {\bf I}}_{n;s} $, where the $\bf
{e}$$_{\nu}$ are orthogonal $\eta_{\mu \nu }=0$ for $\mu \ne
\nu $ and normalized $\eta_{\mu \nu }=+1$ for $p$ space-like
dimensions and $\eta_{\mu \nu }=-1$ for $q$ time-like
dimensions) and where $\bf{I}_{n;s}$ is the identity matrix
whose rank is given by the isomorphisms above. The geometrical
elements are the scalar $\bf{I}_{n;s}$, basis vectors $\bf{e}_
{\nu }$, and their products (bivectors, trivectors, etc.) up to
the pseudo-scalar $n$-volume $\bf{J}_{n;s}~=~\bf{e}_{0}~\bf{e}_
{1}~\bf{\cdot ~\cdot ~\cdot ~e}_{n-1}$. Now $\left( {{\rm {\bf
J}}_{n;s} } \right)^2=(-1)^{\textstyle{{s(s-1)} \over 2}}{\rm
{\bf I}}_{n;s} =\sigma _s {\rm {\bf I}}_{n;s} $. The direct
product of $\bf{R}$$_{n;s}$, with $n$ orthonormal basis vectors
$\bf{e}$$_{\nu }$ with signature $s$, and $\bf{R}$$_{n';s'}$,
with $n'$ orthonormal basis vectors $\bf{e}$$_{\nu '}$ with
signature $s'$, is ${\rm {\bf R}}_{n+n';s+s'\sigma _s } $, with
$n+n'$ orthonormal basis vectors { ${\bf{e}}_{\nu }\otimes \bf{I}
_{n';s'}, \bf{J}_{n;s}\otimes \bf{e}$$_{\nu '}$ } with
signature ${s+s'\sigma _{s}}$, for even positive $n$.
Orthonormal basis vectors for any positive $n$ with any
possible signature can be generated from the two orthonormal
basis vectors of the Minkowskian plane.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.SES.CD.9