×

Coherent distributions for the rigid rotator. (English) Zbl 1347.81056

The rigid rotator is chosen as model for the description of a finite many-particle system, leading to the rotation group \(\mathrm{SO}(3,\mathbb{R})\) as configuration space, while the dynamics is a Hamiltonian flow on \(M=T^* \mathrm{SO}(3,\mathbb{R})\). The Euler parametrization for the rotation group is used, and a description of the invariant vector fields is presented. A classical Hamiltonian is associated with the rigid rotator on the symplectic manifold \((M,\Omega)\). To the elementary rotator \(\mu\) it is associated a classical phase-space \((M_{\mu},\Omega_{\mu})\) and it is constructed the phase-space \((M_{\Gamma},\Omega_{\Gamma})\) consisting of \(N\) identical rotators. A statistical description of the ensemble is considered by a partition of each manifold \(M_{\mu}\) in infinitesimal cells.The distribution function \(F\) of the probability distribution evolves according to Liouville continuity equation on \(M\). The author is looking for a solution \(\Theta|_{\Lambda}=d S\), where \(\Omega =- d\Theta\) and \(\Lambda \) is a Lagrangian submanifold of \(M\), while \(S\) is the generating function of the Hamilton-Jacobi theory. Passing to the Fourier transform of the particular solution, it is obtained the so called coherent solution \(f\), the denomination coming from the fact the time evolution keeps the same aspect. By a formal discretization of the left-invariant vector fields from their Fourier transform in angular momentum, the solution becomes a Wigner-type quasiprobability distribution. The results are compatible with the standard quantization of the anisotropic rotator, with a shift in the expected value of the Hamiltonian. It is shown that when the quasiprobability distribution follows the Liouville equation, the corresponding wave function verifies the time-dependent Schrödinger equation.

MSC:

81S30 Phase-space methods including Wigner distributions, etc. applied to problems in quantum mechanics
70H05 Hamilton’s equations
81S10 Geometry and quantization, symplectic methods
70H20 Hamilton-Jacobi equations in mechanics
35Q41 Time-dependent Schrödinger equations and Dirac equations
53D05 Symplectic manifolds (general theory)

References:

[1] Marsden, J. E., Lectures on Mechanics (1992) · Zbl 0744.70004
[2] Fässler, A.; Khoa, D. T.; Grigorescu, M.; Nojarov, R., Low-lying magnetic dipole excitations in actinide nuclei, Phys. Rev. Lett., 65, 2978 (1990) · doi:10.1103/PhysRevLett.65.2978
[3] Grigorescu, M.; Rompf, D.; Scheid, W., Dynamical effects of deformation in the coupled two-rotor system, Phys. Rev. C, 57, 1218 (1998) · doi:10.1103/PhysRevC.57.1218
[4] Grigorescu, M., Low-lying isovector monopole resonances, J. Phys. G: Nucl. Part. Phys., 16, 417 (1990) · doi:10.1088/0954-3899/16/3/012
[5] Grigorescu, M., Structure effects of the two-protons two-neutrons correlations, Rev. Roum. Phys., 37, 107 (1992)
[6] Landau, L.; Lifchitz, E., Physique Statistique (1967) · Zbl 0144.47605
[7] Einstein, A.; Stern, O., Einige argumente für die annahme einer molekular agitation beim absoluten nullpunkt, Ann. Phys., 40, 551 (1913) · JFM 44.1037.01 · doi:10.1002/andp.19133450309
[8] Śniatycki, J., Geometric Quantization and Quantum Mechanics, 21 (1980) · Zbl 0429.58007
[9] Hurt, N. E., Geometric Quantization in Action: Applications of Harmonic Analysis in Quantum Statistical Mechanics and Quantum Field Theory, 69 (1980)
[10] Prieto, C. T., Quantization and spectral geometry of a rigid body in a magnetic monopole field, Differ. Geom. Appl., 14, 157 (2001) · Zbl 1074.53075 · doi:10.1016/s0926-2245(00)00044-9
[11] Malta, C. P.; Marshall, T. S.; Santos, E., Wigner density of a rigid rotator, Phys. Rev. E, 55, 2551 (1997) · doi:10.1103/PhysRevE.55.2551
[12] Wigner, E. P., On the quantum correction for thermodynamic equilibrium, Phys. Rev., 40, 749 (1932) · Zbl 0004.38201 · doi:10.1103/PhysRev.40.749
[13] Fischer, T.; Gneiting, C.; Hornberger, K., Wigner function for the orientation state, New J. Phys., 15, 063004 (2013) · Zbl 1451.81311 · doi:10.1088/1367-2630/15/6/063004
[14] Grigorescu, M., Classical probability waves, Physica A, 387, 6497 (2008) · doi:10.1016/j.physa.2008.08.012
[15] Grigorescu, M., “Coherent distributions and quantization,” e-print (2014). · Zbl 0849.58036
[16] Sommerfeld, A., Thermodynamik und Statistik (1962) · Zbl 0133.23503
[17] Hirzebruch, F., Neue Topologische Methoden in der Algebraischen Geometrie (1956) · Zbl 0070.16302
[18] Wigner, E. P., Group Theory and its Applications to the Quantum Mechanics of the Atomic Spectra (1959) · Zbl 0085.37905
[19] Barnett, S. M.; Pegg, D. T., Quantum theory of rotation angles, Phys. Rev. A, 41, 3427 (1990) · doi:10.1103/PhysRevA.41.3427
[20] Loss, D.; Müllen, K., Commutation relations for periodic operators, J. Phys. A: Math. Gen., 25, L235 (1992) · doi:10.1088/0305-4470/25/5/005
[21] Ali, S. T.; Führ, H.; Krasowska, A. E., Plancherel inversion as unified approach to wavelet transforms and Wigner functions, Ann. Henri Poincaré, 4, 1015 (2003) · Zbl 1049.81043 · doi:10.1007/s00023-003-0154-4
[22] Naïmark, M.; Stern, A., Théorie des Représentations des Groupes, 341 (1979) · Zbl 0425.22001
[23] Slawianowski, J. J.; Kovalchuck, V.; Martens, A.; Golubowska, B.; Rozko, E., Quasiclassical and quantum systems of angular momentum. Part III. Group algebra 𝔰u(2), quantum angular momentum and quasiclassical asymptotics, J. Geom. Symmetry Phys., 23, 59 (2011) · Zbl 1238.81132 · doi:10.7546/jgsp-23-2011-59-95
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.