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On 3+1 anti-de Sitter and de Sitter Lie bialgebras with dimensionful deformation parameters
We analyze among all possible quantum deformations of the 3+1 (anti)de Sitter
algebras, so(3,2) and so(4,1), which have two specific non-deformed or
primitive commuting operators: the time translation/energy generator and a
rotation. We prove that under these conditions there are only two families of
two-parametric (anti)de Sitter Lie bialgebras. All the deformation parameters
appearing in the bialgebras are dimensionful ones and they may be related to
the Planck length. Some properties conveyed by the corresponding quantum
deformations (zero-curvature and non-relativistic limits, space isotropy,...)
are studied and their dual (first-order) non-commutative spacetimes are also
presented.Comment: 7 pages. Communication presented in the XIII Int.Colloq. Integrable
Systems and Quantum Groups, June 17-19, 2004, Prague, Czech Republic. Some
misprints and dimensions of parameters have been fitte
Non-commutative relativistic spacetimes and worldlines from 2+1 quantum (anti-)de Sitter groups
The -deformation of the (2+1)D anti-de Sitter, Poincar\'e and de
Sitter groups is presented through a unified approach in which the curvature of
the spacetime (or the cosmological constant) is considered as an explicit
parameter. The Drinfel'd-double and the Poisson-Lie structure underlying the
-deformation are explicitly given, and the three quantum kinematical
groups are obtained as quantizations of such Poisson-Lie algebras. As a
consequence, the non-commutative (2+1)D spacetimes that generalize the
-Minkowski space to the (anti-)de Sitter ones are obtained. Moreover,
noncommutative 4D spaces of (time-like) geodesics can be defined, and they can
be interpreted as a novel possibility to introduce non-commutative worldlines.
Furthermore, quantum (anti-)de Sitter algebras are presented both in the known
basis related with 2+1 quantum gravity and in a new one which generalizes the
bicrossproduct one. In this framework, the quantum deformation parameter is
related with the Planck length, and the existence of a kind of "duality"
between the cosmological constant and the Planck scale is also envisaged.Comment: 25 pages. Updated version with more content, comments and reference
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