Related papers: Axion Fragmentation on the Lattice
We use lattice simulations to examine the detailed dynamics of inflaton fragmentation during and after preheating in $\lambda \phi^4$ chaotic inflation. The dynamics are qualitatively similar to preheating after $m^2 \phi^2$ inflation,…
A highly degenerate family of states [proposed in PRB 63, 134503 (2001)] is proven to really minimize the Hamiltonian of the fully frustrated XY model on a dice lattice. The harmonic fluctuations are shown to be no consequence for the…
We study various models of independent particles hopping between energy `traps' with a density of energy barriers $\rho(E)$, on a $d$ dimensional lattice or on a fully connected lattice. If $\rho(E)$ decays exponentially, a true dynamical…
Motivated by recent experimental findings for an organic superconductor, charge oscillations that emerge after a strong pulse of an oscillating electric field is applied are studied in electron systems in a superconducting phase on a…
The axion is a light pseudoscalar particle postulated to solve issues with the Standard Model, including the strong CP problem and the origin of dark matter. In recent years, there has been remarkable progress in the physics of axions in…
The relation between relaxation and diffusion is investigated in a Hamiltonian system of globally coupled rotators. Diffusion is anomalous if and only if the system is going towards equilibrium. The anomaly in diffusion is not anomalous…
We show that the analysis of the time evolution of the occupation of site and momentum modes of harmonically trapped lattice hard-core bosons, under driven dipole oscillations, allows one to determine the energy of the lowest one-particle…
We construct a UV completion of the relaxion in a warped extra dimension. We identify the relaxion with the zero mode of the fifth component of a bulk gauge field and show how hierarchically different decay constants for this field can be…
Using a toy model Lagrangian we investigate the formation of vortices in first order phase transitions. The evolution and interactions of vacuum bubbles are also studied using both analytical approximations and a numerical simulation of…
The rate of energy exchange of spatially localized and gravitationally bound axion configurations with electromagnetic radiation is investigated in presence of strong static magnetic field. Fully analytic treatment is achieved based on…
We discuss the effect of slow phase relaxation and the spin off-diagonal $S$-matrix correlations on the cross section energy oscillations and the time evolution of the highly excited intermediate systems formed in complex collisions. Such…
Oscillating scalar field condensates induce small amplitude oscillations of the Hubble parameter which can induce a decay of the condensate due to a parametric resonance instability [1]. We show that this instability can lead to the decay…
The misalignment mechanism for axion-like particles (ALPs) is a leading explanation for dark matter. In this work we investigate ALPs with non-periodic potentials, which allow for large misalignment of the field from the minimum and make it…
In the frame of an exactly solvable model we calculate electric and magnetic fields created by uniformly moving lattice of Josephson vortices driven by the transport current in the magnetic field parallel to conducting layers. The…
If a theory has more than one classically stable vacuum, quantum tunneling and thermal jumps make the transition between the vacua possible. The transition happens through a first order phase transition started by nucleation of a bubble of…
We construct an analytic solution to Maxwell's equations that violates global charge conservation, by building on the possibilities demonstrated in [Foundations of Physics 49, 330 (2019)]. The construction is valid for a spacetime…
We examine the existence and stability of nonlinear discrete vortex solitons in a square lattice when the standard discrete Laplacian is replaced by a fractional version. This creates a new, effective site-energy term, and a coupling among…
Axial charge production at the early stage of heavy-ion collisions is investigated within the framework of real-time lattice simulations at leading order in QCD coupling. Starting from color glass condensate initial conditions, the time…
In the conventional misalignment mechanism, the axion field has a constant initial field value in the early universe and later begins to oscillate. We present an alternative scenario where the axion field has a nonzero initial velocity,…
Because of their quantum fluctuations, axion fields had a chance to experience field excursions traversing many minima of their potentials during inflation. We study this situation by analyzing the dynamics of an axion-spectator field…