3D phase space of point particle and spinors.

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SUMMARY

The discussion focuses on the connection between the phase space of a point particle in R^3 and isotropic vectors in C^3, specifically addressing the implications of the condition X*X = 0. It establishes that six parameters are necessary to describe the phase space of a point particle, while isotropic vectors form a two-dimensional surface in C^3, parameterized by coordinates z0 and z1. The complex vector Z=(z0, z1) is identified as a spinor, which represents an isotropic three-dimensional complex vector, linking the real part of X to position and the imaginary part to velocity.

PREREQUISITES
  • Understanding of phase space in classical mechanics
  • Familiarity with complex vector spaces, specifically C^3
  • Knowledge of spinors and their mathematical representation
  • Basic concepts of isotropic vectors and their properties
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  • Explore the mathematical properties of isotropic vectors in C^3
  • Study the implications of X*X = 0 on phase space trajectories
  • Investigate the role of spinors in quantum mechanics and their applications
  • Learn about Cartan's work on spinors and their geometric interpretations
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Physicists, mathematicians, and researchers interested in advanced topics in quantum mechanics, particularly those exploring the relationship between classical phase space and complex vector representations.

Spinnor
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Can we make a connection?

Consider the phase space of a point particle in R^3. Six numbers are required, three for position and three for velocity.

Now consider an isotropic vector, X, in C^3 with X*X = 0.
X = (x1,x2,x3), X*X = (x1*x1 + x2*x2 + x3*x3),
x1 = c1 + i*c2, x1*x1 = (c1*c1 + c2*c2 +2*i*c1*c2)

From:

http://www.sjsu.edu/faculty/watkins/spinor.htm

"It can be shown that the set of isotropic vectors in C^3 form a two dimensional surface. This two dimensional surface can be parametrized by two coordinates, z0 and z1 where

z0 = [(x1-ix2)/2]1/2
z1 = i[(x1+ix2)/2]1/2.

The complex two dimensional vector Z=(z0, z1) Cartan calls a spinor. But a spinor is not just a two dimensional complex vector; it is a representation of an isotropic three dimensional complex vector."


Let the real part of X represent the position of a point particle and let the imaginary part of X represent the velocity of the same particle. If we require X*X = 0 how does that restrict the phase space path of a particle?

Thank you for any help.
 
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