Duffin–Kemmer–Petiau algebra

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Short description: Algebra generated by the Duffin-Kemmer-Petiau matrices

In mathematical physics, the Duffin–Kemmer–Petiau algebra (DKP algebra), introduced by R.J. Duffin, Nicholas Kemmer and G. Petiau, is the algebra which is generated by the Duffin–Kemmer–Petiau matrices. These matrices form part of the Duffin–Kemmer–Petiau equation that provides a relativistic description of spin-0 and spin-1 particles.

The DKP algebra is also referred to as the meson algebra.[1]

Defining relations

The Duffin–Kemmer–Petiau matrices have the defining relation[2]

[math]\displaystyle{ \beta^{a} \beta^{b} \beta^{c} + \beta^{c} \beta^{b} \beta^{a} = \beta^{a} \eta^{b c} + \beta^{c} \eta^{b a} }[/math]

where [math]\displaystyle{ \eta^{a b} }[/math] stand for a constant diagonal matrix. The Duffin–Kemmer–Petiau matrices [math]\displaystyle{ \beta }[/math] for which [math]\displaystyle{ \eta^{a b} }[/math] consists in diagonal elements (+1,-1,...,-1) form part of the Duffin–Kemmer–Petiau equation. Five-dimensional DKP matrices can be represented as:[3][4]

[math]\displaystyle{ \beta^{0} = \begin{pmatrix} 0&1&0&0&0\\ 1&0&0&0&0\\ 0&0&0&0&0\\ 0&0&0&0&0\\ 0&0&0&0&0 \end{pmatrix} }[/math], [math]\displaystyle{ \quad \beta^{1} = \begin{pmatrix} 0&0&-1&0&0\\ 0&0&0&0&0\\ 1&0&0&0&0\\ 0&0&0&0&0\\ 0&0&0&0&0 \end{pmatrix} }[/math], [math]\displaystyle{ \quad \beta^{2} = \begin{pmatrix} 0&0&0&-1&0\\ 0&0&0&0&0\\ 0&0&0&0&0\\ 1&0&0&0&0\\ 0&0&0&0&0 \end{pmatrix} }[/math], [math]\displaystyle{ \quad \beta^{3} = \begin{pmatrix} 0&0&0&0&-1\\ 0&0&0&0&0\\ 0&0&0&0&0\\ 0&0&0&0&0\\ 1&0&0&0&0 \end{pmatrix} }[/math]

These five-dimensional DKP matrices represent spin-0 particles. The DKP matrices for spin-1 particles are 10-dimensional.[3] The DKP-algebra can be reduced to a direct sum of irreducible subalgebras for spin‐0 and spin‐1 bosons, the subalgebras being defined by multiplication rules for the linearly independent basis elements.[5]

Duffin–Kemmer–Petiau equation

The Duffin–Kemmer–Petiau equation (DKP equation, also: Kemmer equation) is a relativistic wave equation which describes spin-0 and spin-1 particles in the description of the standard model. For particles with nonzero mass, the DKP equation is[2]

[math]\displaystyle{ (i \hbar \beta^{a} \partial_a - m c) \psi = 0 }[/math]

where [math]\displaystyle{ \beta^{a} }[/math] are Duffin–Kemmer–Petiau matrices, [math]\displaystyle{ m }[/math] is the particle's mass, [math]\displaystyle{ \psi }[/math] its wavefunction, [math]\displaystyle{ \hbar }[/math] the reduced Planck constant, [math]\displaystyle{ c }[/math] the speed of light. For massless particles, the term [math]\displaystyle{ m c }[/math] is replaced by a singular matrix [math]\displaystyle{ \gamma }[/math] that obeys the relations [math]\displaystyle{ \beta^{a} \gamma + \gamma \beta^{a} = \beta^{a} }[/math] and [math]\displaystyle{ \gamma^2 = \gamma }[/math].

The DKP equation for spin-0 is closely linked to the Klein–Gordon equation[4][6] and the equation for spin-1 to the Proca equations.[7] It suffers the same drawback as the Klein–Gordon equation in that it calls for negative probabilities.[4] Also the De Donder–Weyl covariant Hamiltonian field equations can be formulated in terms of DKP matrices.[8]

History

The Duffin–Kemmer–Petiau algebra was introduced in the 1930s by R.J. Duffin,[9] N. Kemmer[10] and G. Petiau.[11]

Further reading

References

  1. Helmstetter, Jacques; Micali, Artibano (2010-03-12). "About the Structure of Meson Algebras". Advances in Applied Clifford Algebras (Springer Science and Business Media LLC) 20 (3–4): 617–629. doi:10.1007/s00006-010-0213-0. ISSN 0188-7009. 
  2. 2.0 2.1 See introductory section of: Pavlov, Yu V. (2006). "Duffin–Kemmer–Petiau equation with nonminimal coupling to curvature". Gravitation & Cosmology 12 (2–3): 205–208. 
  3. 3.0 3.1 See for example Boztosun, I.; Karakoc, M.; Yasuk, F.; Durmus, A. (2006). "Asymptotic iteration method solutions to the relativistic Duffin-Kemmer-Petiau equation". Journal of Mathematical Physics 47 (6): 062301. doi:10.1063/1.2203429. ISSN 0022-2488. 
  4. 4.0 4.1 4.2 Capri, Anton Z. (2002). Relativistic quantum mechanics and introduction to quantum field theory. River Edge, NJ: World Scientific. p. 25. ISBN 981-238-136-8. OCLC 51850719. https://books.google.com/books?id=tTJHB5hepQUC&pg=PA25. 
  5. Fischbach, Ephraim; Nieto, Michael Martin; Scott, C. K. (1973). "Duffin‐Kemmer‐Petiau subalgebras: Representations and applications". Journal of Mathematical Physics (AIP Publishing) 14 (12): 1760–1774. doi:10.1063/1.1666249. ISSN 0022-2488. 
  6. Casana, R; Fainberg, V Ya; Lunardi, J T; Pimentel, B M; Teixeira, R G (2003-05-16). "Massless DKP fields in Riemann–Cartan spacetimes". Classical and Quantum Gravity 20 (11): 2457–2465. doi:10.1088/0264-9381/20/11/333. ISSN 0264-9381. 
  7. Kruglov, Sergey (2001). Symmetry and electromagnetic interaction of fields with multi-spin. Huntington, N.Y.: Nova Science Publishers. p. 26. ISBN 1-56072-880-9. OCLC 45202093. https://books.google.com/books?id=E6Elkxs9PaIC&pg=PA26. 
  8. Kanatchikov, Igor V. (2000). "On the Duffin-Kemmer-Petiau formulation of the covariant Hamiltonian dynamics in field theory". Reports on Mathematical Physics 46 (1–2): 107–112. doi:10.1016/s0034-4877(01)80013-6. ISSN 0034-4877. 
  9. Duffin, R. J. (1938-12-15). "On The Characteristic Matrices of Covariant Systems". Physical Review (American Physical Society (APS)) 54 (12): 1114. doi:10.1103/physrev.54.1114. ISSN 0031-899X. 
  10. N. Kemmer (1939-11-10). "The particle aspect of meson theory". Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences (The Royal Society) 173 (952): 91–116. doi:10.1098/rspa.1939.0131. ISSN 0080-4630. http://rspa.royalsocietypublishing.org/content/173/952/91.full.pdf+html. 
  11. G. Petiau, University of Paris thesis (1936), published in Acad. Roy. de Belg., A. Sci. Mem. Collect.vol. 16, N 2, 1 (1936)