相关论文: Negative Modes of Oscillating Instantons

We analyze long-time behavior of solutions to a class of problems related to very fast and singular diffusion porous medium equations having nonhomogeneous in space and time source terms with zero mean. In dimensions two and three, we…

We propose a new mechanism for stabilization of confined modes in lasers and semiconductor microcavities holding exciton-polariton condensates, with spatially uniform linear gain, cubic loss, and cubic self-focusing or defocusing…

We demonstrate that possession of a single negative mode is not a sufficient criterion for an instanton to mediate exponential decay. For example, de Sitter space is generically stable against decay via the Coleman-De Luccia instanton. This…

In this article, we consider the problem of homogenising the linear heat equation perturbed by a rapidly oscillating random potential. We consider the situation where the space-time scaling of the potential's oscillations is \textit{not}…

We investigate theoretically the electromechanical properties of freely suspended nanowires that are in tunnelling contact with the tip of a scanning tunnelling microscope (STM) and two supporting metallic leads. The aim of our analysis is…

Previous studies of linearized stability of asymptotically flat Euclidean axion wormholes found that symmetric modes suffered from divergences. We show that such divergences were an artifact of a particular way of solving the constraints,…

Oscillons are spatially stationary, quasi-periodic solutions of nonlinear field theories seen in settings ranging from granular systems, low temperature condensates and early universe cosmology. We describe a new class of oscillon in which…

We show that $QCD_2$ with adjoint fermions involves instantons due to nontrivial $\pi_1[SU(N)/Z_N]~=~Z_N$. At high temperatures, quasiclassical approximation works and the action and the form of effective (with account of quantum…

I construct a simple model of the convective burning layer during a type I X-ray burst to investigate the effects convection has on the stability of the layer to nonradial oscillations. A linear perturbation analysis demonstrates that the…

We present exact inhomogeneous and anisotropic cosmological solutions of low-energy string theory containing dilaton and axion fields. The spacetime metric possesses cylindrical symmetry. The solutions describe ever-expanding universes with…

Throughout this paper, we comprehensively study instantons with every kind of continuous conformal symmetry. Examples of these objects are hard to come by due to non-linear constraints. However, by applying previous work on moduli spaces,…

We connect the translation modes of the instanton in the two-dimensional Abelian Higgs model with local translations of the vortex of the related model in (3+1) dimensions, the Nielsen-Olesen vortex. In this context these modes describe…

It has been suggested that quasi-periodic oscillations of accreting X-ray sources may relate to the modes named in the title. We consider non-axisymmetric linear perturbations to an isentropic, isothermal, unmagnetized thin accretion disk.…

We study two-flavor neutrino oscillations in homogeneous neutrino gases in which neutrinos and anti-neutrinos are in nearly pure weak interaction states initially. We find that the monopole and dipole oscillation modes can trigger flavor…

We consider a (1+1) dimensional scalar field theory that supports oscillons, which are localized, oscillatory, stable solutions to nonlinear equations of motion. We study this theory in an expanding background and show that oscillons now…

We study the global structure of vacua of heterotic strings compactified on orbifolds $T^4/Z_N$ (N=2,3) in the presence of heterotic 5-branes. Gauge symmetry breaking associated with orbifold is described by instantons in the field theory.…

We have obtained exact analytical expressions in closed form, for the linear modes excited in finite and discrete systems that are driven by a spatially homogeneous alternating field. Those modes are extended for frequencies within the…

We introduce a homogenization approach to characterize the dynamical response of a generic dispersive spacetime crystal in the long-wavelength limit. The theory is applied to dispersive spacetime platforms with a travelling-wave modulation.…

This paper is devoted mainly to mathematical aspects of modeling and simulation of tunnel relaxation of nonequilibrium charged oxide traps located at/near the interface insulator - conductive channel, for instance in irradiated MOS devices.…

In the two-dimensional CP(N-1) model one can parametrize exact many-instanton solutions via N `constituents' (called `zindons'). This parameterization allows, in principle, a complete `melting' of individual instantons. The model is…