Related papers: Instantons: thick-wall approximation
Using numerical and analytic methods, we study quantum tunneling from a Minkowski false vacuum to an anti-de Sitter true vacuum. Scanning the parameter space of theories with quartic and non-polynomial potentials, we find that for any given…
Using a new approach to the analysis of false vacuum decay based on the so-called tunneling potential, we develop a general method to find scalar potentials with a false vacuum with exactly solvable decay at the semi-classical level,…
Scalar field theory with an asymmetric potential is studied at zero temperature and high-temperature for $\phi^6$ potential. The equations of motion are solved numerically to obtain O(4) spherical symmetric and O(3) cylindrical symmetric…
We perform a precise analytic test of the instanton approximation by comparing the exact band spectrum of the periodic Lam\'e potential to the tight-binding, instanton and WKB approximations. The instanton result gives the correct leading…
Instanton theory has arisen as a practical tool for calculating tunneling splittings in molecular systems. Unfortunately, the original formulation of instanton theory fundamentally breaks down when trying to calculate the level splitting in…
We investigate false vacuum decay of a relativistic scalar field initialized in the metastable minimum of an asymmetric double-well potential. The transition to the true ground state is a well-defined initial-value problem in real time,…
Some years ago, Atiyah and Manton described a method to construct approximate Skyrmion solutions from Yang-Mills instantons. Here we present a dynamical realization of this construction using domain walls in a five-dimensional gauge theory.…
We numerically study the evolution of a classical real scalar field in ${(1+1)}$ dimensions with initial conditions describing thermal fluctuations around a metastable vacuum. We track false vacuum decay in real time and compare several…
Transition pathways of stochastic dynamical systems are typically approximated by instantons. Here we show, using a dynamical system containing two competing pathways, that at low-to-intermediate temperatures, instantons can fail to capture…
Vacuum decay posits that the universe's apparent vacuum is metastable and could transition to a lower-energy state. According to current physics models, if such a transition occurred in any location, a region of "true vacuum" would…
We study the effect of the Gauss-Bonnet term on vacuum decay process in the Coleman-De Luccia formalism. The Gauss-Bonnet term has an exponential coupling with the real scalar field, which appears in the low energy effective action of…
The standard bounce formalism for calculating the decay rate of a metastable vacuum cannot be applied to theories in which the symmetry breaking is due to radiative corrections, because in such theories the tree-level action has no bounce…
We introduce a new picture of vacuum decay which, in contrast to existing semiclassical techniques, provides a real-time description and does not rely on classically-forbidden tunneling paths. Using lattice simulations, we observe vacuum…
We investigate the role of nonperturbative, bubble-like inhomogeneities on the decay rate of false-vacuum states in two and three-dimensional scalar field theories. The inhomogeneities are induced by setting up large-amplitude oscillations…
The false vacuum is a metastable state that can occur in quantum field theory, and its decay was first studied semi-classically by Coleman. In this work we consider the 1+1 dimensional $\varphi^4$ theory, which is the simplest model that…
Within the framework of the instanton approach we present analytical results for the following model problems: (i) particle penetration through a parabolic potential barrier, where the instanton solution practically coincides with the exact…
We derive the general equations of motion for a braneworld containing a (localized) domain wall. Euclideanization gives the geometry for braneworld false vacuum decay. We explicitly derive these instantons and compute the amplitude for…
I show that cosmological bubble walls in the thin wall approximation are unstable to the creation of "barnacles" -- loci of different wall tension adjacent to regions filled with a third vacuum. Barnacle formation leads to the same…
Coleman and De Luccia (CDL) showed that gravitational effects can prevent the decay by bubble nucleation of a Minkowski or AdS false vacuum. In their thin-wall approximation this happens whenever the surface tension in the bubble wall…
The imaginary part of the one loop effective action in external backgrounds can be efficiently computed using worldline instantons which are closed periodic paths in spacetime. Exact solutions for nonstatic backgrounds are only known in…