We study the ground state and the collective excitations of parabolicallyconfined double-layer quantum dot systems in a strong magnetic field. We identify parameter regimes where electrons form maximum density droplet states, quantum-dot analogs of the incompressible states of the bulk integer quantum Hall effect. In these regimes the Hartree-Fock approximation and the time-dependent Hartree-Fo...

We find the evolution of arbitrary excitations on 2-charge supertubes, by mapping the supertube to a string carrying traveling waves. We argue that when the coupling is increased from zero the energy of excitation leaks off to infinity, and when the coupling is increased still further a new set of long lived excitations emerge. We relate the excitations at small and large couplings to excitatio...

We study interactions amongst topologically conserved excitations of quantum theories of gravity, in particular the braid excitations of four valent spin networks. These have been shown previously to propagate and interact under evolution rules of spin foam models. We show that the dynamics of these braid excitations can be described by an effective theory based on Feynman diagrams. In this lan...

We discuss the process by which energy, initially evenly distributed in a nonlinear lattice, can localize itself into large amplitude excitations. We show that, the standard modulational instability mechanism, which can initiate the process by the formation of small amplitude breathers, is completed efficiently, in the presence of discreteness, by energy exchange mechanisms between the nonlinea...

A nonlinear energy sink is designed to control the oscillations of a 2 degrees-of-freedom pendulum under following types excitations: horizontal and vertical base displacements initial energy. Coupled governing system equations are treated with multiple-scale methods different assumptions depending on applied loads. Fast slow dynamics revealed leading detection possible dynamical regimes. The c...

We analyze the origin and features of localized excitations in a discrete two-dimensional Hamiltonian lattice. The lattice obeys discrete translational symmetry, and the localized excitations exist because of the presence of nonlinearities. We connect the presence of these excitations with the existence of local integrability of the original N degree of freedom system. On the basis of this expl...

The rich correlation physics in two-dimensional (2D) electron systems is governed by the dispersion of its excitations. In the fractional quantum Hall regime, excitations involve fractionally charged quasi particles, which exhibit dispersion minima at large momenta referred to as rotons. These rotons are difficult to access with conventional techniques because of the lack of penetration depth o...

We show that the Néel states of two-dimensional antiferromagnets have low energy vector boson excitations in the vicinity of deconfined quantum critical points. We compute the universal damping of these excitations arising from spin-wave emission. Detection of such a vector boson will demonstrate the existence of emergent topological gauge excitations in a quantum spin system.