Exotic Phase Space Dynamics Generated by Orthogonal Polynomial Self-interactions

The phase space dynamics generated by different orthogonal polynomial self-interactions exhibited in higher order nonlinear Schr\"{o}dinger equation (NLSE) are often less intuitive than those ofcubic and quintic nonlinearities. Even for nonlinearities as simple as a cubic in NLSE, the dynamics for generic initial states shows surprising features. In this Letter, for the first time, we identify the higher-order nonlinearities in terms of orthogonal polynomials in the generalized NLSE/GPE. More pertinently, we explicate different exotic phase space structures for three specific examples: (i) Hermite, (ii) Chebyshev, and (iii) Laguerre polynomial self-interactions. For the first two self-interactions, we exhibit that the alternating signs of the various higher-order nonlinearities are naturally embedded in these orthogonal polynomials that confirm to the experimental conditions. To simulate the phase-space dynamics that bring about by the Laguerre self-interactions, a source term should {\it necessarily} be included in the modified NLSE/GPE. Recent experiments suggest that this modified GPE captures the dynamics of self-bound quantum droplets, in the presence of external source

Time dependent non-Abelian waves and their stochastic regimes for gauge fields coupled to external sources

In this paper we explore explicit exact solutions of the $SU(2)$ Yang-Mills (YM) and Yang-Mill-Higgs (YMH) equations with homogeneous and inhomogeneous external sources. Whereas in the case of YM we have confirmed our analytical findings with the numerical simulations, the numerical corroborations in the YMH case yielded the stochastic character of motion for the ensuing fields.Comment: 6 pages 16 Figure

Classical solutions for Yang-Mills-Chern-Simons field coupled to an external source

We find wide class of exact solutions of Yang-Mills-Chern-Simons theory coupled to an external source, in terms of doubly periodic Jacobi elliptic functions. The obtained solutions include localized solitons, trigonometric solutions, pure cnoidal waves, and singular solutions in certain parameter range. Furthermore, it is observed that these solutions exist over a nonzero background.Comment: 5 page

Sinusoidal Excitations in Two Component Bose-Einstein Condensates

The non-linear coupled Gross-Pitaevskii equation governing the dynamics of the two component Bose-Einstein condensate (TBEC) is shown to admit pure sinusoidal, propagating wave solutions in quasi one dimensional geometry. These solutions, which exist for a wide parameter range, are then investigated in the presence of a harmonic oscillator trap with time dependent scattering length. This illustrates the procedure for coherent control of these modes through temporal modulation of the parameters, like scattering length and oscillator frequency. We subsequently analyzed this system in an optical lattice, where the occurrence of an irreversible phase transition from superfluid to insulator phase is seen.Comment: 6 pages, 1 figur