Related papers: The lambda Phi^4 Miracle: lattice data and the zer…
Does massless (lambda Phi^4)_4 theory exhibit spontaneous symmetry breaking (SSB)? The raw 1-loop result implies that it does, but the "RG-improved" result implies the opposite. I argue that the appropriate "low-energy effective theory" is…
We calculate the explicit expression of the effective potential in a $\lambda\phi^4$ theory at finite temperature in a static universe for arbitrary spacetime dimensions (2\leq D < 5). To study the combined effects of the temperature and…
A lattice simulation in the broken phase of four-dimensional (lambda Phi^4) theory in the Ising limit suggests that, in the continuum limit, the scalar condensate rescales by a factor different from the conventional wavefunction…
It has been shown recently that the mathematical status of the operator product expansion (OPE) is better than was expected before: namely considering massive Euclidean $\varphi^4$-theory in the perturbative loop expansion, the OPE…
We present a self-consistent calculation of the finite temperature effective potential for $\lambda \Phi^4$ theory in four dimensions using a composite operator effective action. We find that in a spontaneously broken theory not only the…
We investigate whether the six-loop beta function of the $\lambda \phi^4_4$ theory exhibits evidence for an ultraviolet zero. As part of our analysis, we calculate and analyze Pad\'e approximants to this beta function. Extending our earlier…
In this work we consider the one-loop effective action of a self-interacting $\lambda\phi^{4}$ field propagating in a $D$ dimensional Euclidean space endowed with $d\leq D$ compact dimensions. The main purpose of this paper is to compute…
We use Monte Carlo simulations to obtain an improved lattice measurement of the critical coupling constant [lambda / mu^2]_crit for the continuum (1 + 1)-dimensional (lambda / 4) phi^4 theory. We find that the critical coupling constant…
Corrections to scaling in the two-dimensional scalar phi^4 model are studied based on non-perturbative analytical arguments and Monte Carlo (MC) simulation data for different lattice sizes L (from 4 to 1536) and different values of the…
Using lattice simulations of a one-component $(\lambda \Phi^4)_4$ theory, we have measured the energy spectrum $\omega({\mathbf{k}})$ in the broken phase at various lattice sizes. Our data show that the energy-gap $\omega(0)$ is {\it not}…
We analyze universal and nonuniversal finite-size effects of lattice systems in a $L^d$ geometry above the upper critical dimension d = 4 within the O(n) symmetric $\phi^4$ lattice theory. On the basis of exact results for $n \to\infty$ and…
In this work, we use a specific parameterization of the hypergeometric approximants ( the one by Mera et.al in Phys. Rev. Let. 115, 143001 (2015)) to approximate the seven-loop critical exponent $\nu$ for the $O(2)$-symmetric $\phi^4$…
We point out that there is a missing portion in the two-loop effective potential of the massless O(N) phi^4 theory obtained by Jackiw in his classic paper, Phys. Rev. D 9, 1686 (1974).
We carry a Monte Carlo study of the coupled two-scalar $\lambda\phi^2_1 \phi^2_2$ model in three dimensions. We find no trace of Inverse Symmetry Breaking in the region of negative $\lambda$'s for which the one-loop effective potential…
The effective potential for the local composite operator $\phi^{2}(x)$ in $\lambda \phi^{4}$-theory is investigated at finite temperature in an approach based on path-integral linearisation of the $\phi^4 $-interaction. At zero temperature,…
The low-energy spectrum of a one-component, spontaneously broken \Phi^4 theory is generally believed to have the same simple massive form \sqrt{{\bf p}^2 + m^2_h} as in the symmetric phase where < \Phi >=0. However, in lattice simulations…
We study a scenario based upon a mass-less $\lambda \phi^4$ theory coupled to massive neutrino matter with $Z_2$ symmetry using a conformal coupling, $A(\phi)=1-\alpha\phi^2/2M_{pl}^2;~\alpha=M^2_{pl}/M^2$ where $M$ is a cut off mass. The…
The three-loop effective potential of the massless O(N) $\phi^4$ theory is calculated analytically using techniques of dimensional regularization. We see a complete agreement between our result and Jackiw's result obtained only up to…
We present a Monte Carlo study of the one-component $\phi^4$ model on the cubic lattice in three dimensions. Leading order scaling corrections are studied using the finite size scaling method. We compute the corrections to scaling exponent…
As an application of perfect lattice perturbation theory, we construct an O(\lambda) perfect lattice action for the anharmonic oscillator analytically in momentum space. In coordinate space we obtain a set of 2-spin and 4-spin couplings…