**Stephen P. King** (*stephenk1@home.com*)

*Sat, 27 Mar 1999 08:47:22 -0500*

**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]**Next message:**Hitoshi Kitada: "[time 63] RE: [time 59]: From Doug Sweetser"**Previous message:**Hitoshi Kitada: "[time 61] RE: [time 57] Re: [time 52] Orientation of time"

Hi all,

For all Clifford algebra fans! :)

"Standard formulation is unable to distinguish between the (+++-) and

(---+) spacetime metric signatures.

However, the Clifford algebras associated with each are

inequivalent, R(4) in the first case (real 4 by 4 matrices), H(2) in the

latter (quaternionic 2 by 2). Multivector reformulations of Dirac theory

by various authors look quite inequivalent pending the algebra assumed.

It is not clear if this is mere artifact, or if there is a right/wrong

choice as to which one describes reality. However, recently it has been

shown that one can map from one signature to the other using a "tilt

transformation" [see P. Lounesto, "Clifford Algebras and Hestenes

Spinors", Found. Phys. 23, 1203-1237 (1993)]. The broader question is

that if the universe is signature blind, then perhaps a complete theory

should be manifestly tilt covariant. A generalized multivector wave

equation is proposed which is fully signature invariant in form, because

it includes all the components of the algebra in the wavefunction

(instead of restricting it to half) as well as all the possibilities for

interaction terms."

http://xxx.lanl.gov/abs/gr-qc/9704048

**Next message:**Hitoshi Kitada: "[time 63] RE: [time 59]: From Doug Sweetser"**Previous message:**Hitoshi Kitada: "[time 61] RE: [time 57] Re: [time 52] Orientation of time"

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