33 research outputs found
Superintegrable systems, polynomial algebra structures and exact derivations of spectra
Superintegrable systems are a class of physical systems which possess more
conserved quantities than their degrees of freedom. The study of these systems
has a long history and continues to attract significant international
attention. This thesis investigates finite dimensional quantum superintegrable
systems with scalar potentials as well as vector potentials with monopole type
interactions. We introduce new families of -dimensional superintegrable
Kepler-Coulomb systems with non-central terms and double singular harmonic
oscillators in the Euclidean space, and new families of superintegrable Kepler,
MIC-harmonic oscillator and deformed Kepler systems interacting with
Yang-Coulomb monopoles in the flat and curved Taub-NUT spaces. We show their
multiseparability and obtain their Schr\"{o}dinger wave functions in different
coordinate systems. We show that the wave functions are given by (exceptional)
orthogonal polynomials and Painlev\'{e} transcendents (of hypergeometric type).
We construct higher-order algebraically independent integrals of motion of the
systems via the direct and constructive approaches. These integrals form
(higher-rank) polynomial algebras with structure constants involving Casimir
operators of certain Lie algebras. We obtain finite dimensional unitary
representations of the polynomial algebras and present the algebraic
derivations for degenerate energy spectra of these systems. Finally, we present
a generalized superintegrable Kepler-Coulomb model from exceptional orthogonal
polynomials and obtain its energy spectrum using both the separation of
variable and the algebraic methods.Comment: PhD Thesis, School of Mathematics and Physics, The University of
Queensland, Australia, January 2018, 175 page
Quadratic symmetry algebras and spectrum of the 3D nondegenerate quantum superintegrable system
In this paper, we present the quadratic associative symmetry algebra of the
3D nondegenerate maximally quantum superintegrable system. This is the complete
symmetry algebra of the system. It is demonstrated that the symmetry algebra
contains suitable quadratic subalgebras, each of which is generated by three
generators with relevant structure constants, which may depend on central
elements. We construct corresponding Casimir operators and present
finite-dimensional unirreps and structure functions via the realizations of
these subalgebras in the context of deformed oscillators. By imposing
constraints on the structure functions, we obtain the spectrum of the 3D
nondegenerate superintegrable system. We also show that this model is
multiseparable and admits separation of variables in cylindrical polar and
paraboloidal coordinates. We derive the physical spectrum by solving the
Schr\"{o}dinger equation of the system and compare the result with those
obtained from algebraic derivations.Comment: 21 page
Family of nonstandard integrable and superintegrable classical Hamiltonian systems in non-vanishing magnetic fields
In this paper we present the construction of all nonstandard integrable
systems in magnetic fields whose integrals have leading order structure
corresponding to the case (i) of Theorem 1 in [A Marchesiello and L \v{S}nobl
2022 {\it J. Phys. A: Math. Theor.} {\bf 55} 145203]. We find that the
resulting systems can be written as one family with several parameters. For
certain limits of these parameters the system belongs to intersections with
already known standard systems separating in Cartesian and / or cylindrical
coordinates and the number of independent integrals of motion increases, thus
the system becomes minimally superintegrable. These results generalize the
particular example presented in section 3 of [A Marchesiello and L \v{S}nobl
2022 {\it J. Phys. A: Math. Theor.} {\bf 55} 145203].Comment: 18 page