×

New parameterizations of \(\mathrm{SL}(2,\mathbb{R})\) and some explicit formulas for its logarithm. (English) Zbl 1489.22014

The exponential map for Lie groups has been extensively studied and it is neither injective nor surjective in general, as it is already the case for \(\mathrm{SL}(2,\mathbb R)\), the Lie group of invertible \(2\times 2\) real matrices. In the paper under review, the authors give a new parametrization of \(\mathrm{SL}(2,\mathbb R)\) and derive explicit formulas for the inverse of the exponential map. Moreover a geometric description of the field of values of matrices in \(\mathrm{SL}(2,\mathbb R)\) is given in terms of ellipses.
Reviewer: Salah Mehdi (Metz)

MSC:

22E70 Applications of Lie groups to the sciences; explicit representations
17B81 Applications of Lie (super)algebras to physics, etc.
81R05 Finite-dimensional groups and algebras motivated by physics and their representations

References:

[1] Barut A., Zeni J., and Laufer A., The Exponential Map for the Conformal Group O(2, 4), J. Phys. A: Math. & Gen. 27 (1994) 5239-5250. · Zbl 0840.22034
[2] Engø K., On the BCH-Formula in so(3), BIT 41 (2001) 629-632. · Zbl 0988.22009
[3] Gilmore R., Relations among Low-Dimensional Simple Lie Groups, J. Geom. Symmetry Phys. 28 (2012) 1-45. · Zbl 1317.22005
[4] Goto M. and Grosshans F., Semisimple Lie Algebras, Lecture Notes in Pure and Applied Mathematics 38, Marcel Dekker, New York 1978. · Zbl 0391.17004
[5] Gürsey F., Introduction to Group Theory, In: Relativity, Groups and Topol-ogy, C. DeWitt and Bryce DeWitt (Eds.), Gordon and Breach, New York 1964, pp. 91-164. · Zbl 0163.02401
[6] Iachello F., Lie Algebras and Applications, Springer, Berlin 2015. · Zbl 1326.81005
[7] Johnson C., Computation of the Field of Values of a 2×2 Matrix, J. Res. Natl. Bureau Standards B -Math. Sci. 78 (1974) 105-107. · Zbl 0295.15010
[8] Lenz R., Group Theoretical Methods in Image Processing, Springer, Berlin 1990. · Zbl 0845.68119
[9] Marle Ch.-M., Symmetries of Hamiltonian Dynamical Systems, Momentum Maps and Reductions, Geom. Integrability & Quantization 15 (2014) 11-52. · Zbl 1318.53095
[10] Mladenova C., Group Theory in the Problems of Modeling and Control of Multi-Body Systems, J. Geom. Symmetry Phys. 8 (2006) 17-121. · Zbl 1121.70007
[11] Mladenova C. and Mladenov I., Cayley Map for Symplectic Groups, Geom. Integrability & Quantization 22 (2021) 154-164. · Zbl 1484.22016
[12] Mladenov I., Raychev P., and Roussev R., Geometric Quantization of a Re-stricted Sympectic Model of Collective Nuclear Motion, Bulg. J. Phys. 13 (1986) 13-26. · Zbl 0596.58022
[13] Qiao Zh. and Dick R., Matrix Logarithms and Range of the Exponential Maps for the Symmetry Groups SL(2, R), SL(2, C), and the Lorentz Group, J. Phys. Commun. 3 (2019) 075008 (17pp).
[14] Rosensteel G., Self-Gravitating Symplectic Systems, Astrophys. J. 416 (1993) 291-302.
[15] Ungar A., Hyperbolic Geometry, Geom. Integrability & Quantization 15 (2013) 259-282. · Zbl 1325.51012
[16] Wolf K., Geometric Optics on Phase Space, Springer, Berlin 2004. · Zbl 1057.78001
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.