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 SIGMA 8 (2012), 013, 15 pages      arXiv:1006.0478     
https://doi.org/10.3842/SIGMA.2012.013 
Exponential Formulas and Lie Algebra Type Star Products
Stjepan Meljanac a,  Zoran Škoda a and Dragutin Svrtan b
 a) Division for Theoretical Physics, Institute Rudjer Bošković, Bijenička 54, P.O. Box 180, HR-10002 Zagreb, Croatia
 b) Department of Mathematics, Faculty of Natural Sciences and Mathematics, University of Zagreb, HR-10000 Zagreb, Croatia
 
 
Received May 26, 2011, in final form March 01, 2012; Published online March 22, 2012 
Abstract
 
Given formal differential operators $F_i$ on polynomial algebra
in several variables $x_1,\ldots,x_n$, we discuss finding expressions
$K_l$ determined by the equation $\exp(\sum_i x_i F_i)(\exp(\sum_j q_j x_j)) =
\exp(\sum_l K_l x_l)$ and their applications. The expressions for $K_l$
are related to the coproducts for deformed momenta
for the noncommutative space-times
of Lie algebra type and also appear in the
computations with a class of star products.
We find combinatorial recursions
and derive formal differential equations for finding $K_l$.
We elaborate an example for a Lie algebra $su(2)$, related to a
quantum gravity application from the literature.
  
 Key words:
star product; exponential expression; formal differential operator. 
pdf (439 kb)  
tex (25 kb)
 
 
References
 
- Amelino-Camelia G., Arzano M., Coproduct and star product in field theories on
  Lie-algebra noncommutative space-times, Phys. Rev. D 65
  (2002), 084044, 8 pages, hep-th/0105120.
 
- Arnal D., Cortet J.C., $*$-products in the method of orbits for nilpotent
  groups, J. Geom. Phys. 2 (1985), 83-116.
 
- Arnal D., Cortet J.C., Molin P., Pinczon G., Covariance and geometrical
  invariance in $*$ quantization, J. Math. Phys. 24
  (1983), 276-283.
 
- Aschieri P., Lizzi F., Vitale P., Twisting all the way: from classical
  mechanics to quantum fields, Phys. Rev. D 77 (2008),
  025037, 16 pages, arXiv:0708.3002.
 
- Barron K., Huang Y.Z., Lepowsky J., Factorization of formal exponentials and
  uniformization, J. Algebra 228 (2000), 551-579,
  math.QA/9908151.
 
- Bayen F., Flato M., Fronsdal C., Lichnerowicz A., Sternheimer D., Deformation
  theory and quantization. I. Deformations of symplectic structures,
  Ann. Physics 111 (1978), 61-110.
 
- Bayen F., Flato M., Fronsdal C., Lichnerowicz A., Sternheimer D., Deformation
  theory and quantization. II. Physical applications, Ann. Physics
  111 (1978), 111-151.
 
- Blasiak P., Flajolet P., Combinatorial models of creation-annihilation,
  Ann. Physics 65 (2011), Art. B65c, 78 pages,
  arXiv:1010.0354.
 
- Borowiec A., Pacho A., $\kappa$-Minkowski spacetimes and DSR algebras:
  fresh look and old problems, SIGMA 6 (2010), 086, 31 pages,
  arXiv:1005.4429.
 
- Dimitrijević M., Meyer F., Möller L., Wess J., Gauge theories on the
  $\kappa$-Minkowski spacetime, Eur. Phys. J. C Part. Fields
  36 (2004), 117-126, hep-th/0310116.
 
- Durov N., Meljanac S., Samsarov A., Škoda Z., A universal formula for
  representing Lie algebra generators as formal power series with
  coefficients in the Weyl algebra, J. Algebra 309 (2007),
  318-359, math.RT/0604096.
 
- Freidel L., Livine E.R., 3D quantum gravity and effective noncommutative
  quantum field theory, Phys. Rev. Lett. 96 (2006), 221301,
  4 pages, hep-th/0512113.
 
- Freidel L., Majid S., Noncommutative harmonic analysis, sampling theory and the
  Duflo map in 2+1 quantum gravity, Classical Quantum Gravity
  25 (2008), 045006, 37 pages, hep-th/0512113.
 
- Halliday S., Szabo R.J., Noncommutative field theory on homogeneous
  gravitational waves, J. Phys. A: Math. Gen. 39 (2006),
  5189-5225, hep-th/0602036.
 
- Kathotia V., Kontsevich's universal formula for deformation quantization and
  the Campbell-Baker-Hausdorff formula, Internat. J. Math.
  11 (2000), 523-551, math.QA/9811174.
 
- Kontsevich M., Deformation quantization of Poisson manifolds, Lett.
  Math. Phys. 66 (2003), 157-216, q-alg/9709040.
 
- Meljanac S., Krešić-Jurić S., Stojić M., Covariant
  realizations of kappa-deformed space, Eur. Phys. J. C Part. Fields
  51 (2007), 229-240, hep-th/0702215.
 
- Meljanac S., Škoda Z., Leibniz rules for enveloping algebras, arXiv:0711.0149, the latest version
  available at http://www.irb.hr/korisnici/zskoda/scopr5.pdf.
 
- Meljanac S., Stojić M., New realizations of Lie algebra kappa-deformed
  Euclidean space, Eur. Phys. J. C Part. Fields 47 (2006),
  531-539, hep-th/0605133.
 
- Raševski P.K., Associative superenvelope of a Lie algebra and its
  regular representation and ideals, Trudy Moskov. Mat. Obšč.
  15 (1966), 3-54.
 
- Škoda Z., Heisenberg double versus deformed derivatives,
  Internat. J. Modern Phys. A 26 (2011), 4845-4854,
  arXiv:0909.3769.
 
- Škoda Z., Twisted exterior derivatives for enveloping algebras,
  arXiv:0806.0978.
 
 
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