Related papers: The impossible regularization of the Nambu Jona-La…
We employ the method of differential regularization to calculate explicitly the one-loop effective action of a bosonized $U_L(3)\times U_R(3)$ extended Nambu--Jona-Lasinio model consisting of scalar, pseudoscalar, vector and axial vector…
We consider Euclidean functional integrals involving actions which are not exclusively real. This situation arises, for example, when there are $t$-odd terms in the the Minkowski action. Writing the action in terms of only real fields…
A novel strategy to handle divergences typical of perturbative calculations is implemented for the Nambu--Jona-Lasinio model and its phenomenological consequences investigated. The central idea of the method is to avoid the critical step…
Two variants of the Nambu--Jona-Lasinio model -- the model with 4-dimensional cutoff and the model with dimensionally-analytical regularization -- are systematically compared. It is shown that they are, in essence, two different models of…
The vacuum contribution to quark matter under a uniform magnetic field within the SU(3) version of the Nambu and Jona-Lasinio model is studied. The standard regularization procedure is examined and a new prescription is proposed. For this…
The Nambu--Jona-Lasinio model is widely used to study strong-interaction phenomena in vacuum and quark matter. Since the model is nonrenormalizable, one needs to work within a specific regularization scheme to obtain finite results. Here we…
The imaginary part of the effective action encodes vacuum instability and particle production in the background field. Two standard approaches are commonly used to derive it: the Bogoliubov method and the Green's function method, which are…
We analyze the analytic structure of meson propagators in the Nambu--Jona-Lasinio model with a proper-time regulator. We show that the regulator produces unphysical complex singularities. As a result the naive use of the Wick rotation is no…
The soliton formation is considered in the Nambu-Jona-Lasinio model with local four quark interaction and various schemes to regularize the energy contribution of the polarized vacuum. No additional constraints are admitted in order to…
We derive the effective action for pseudoscalar mesons by integrating out vector and axial--vector collective fields in the generating functional of the bosonized NJL--model. The corresponding modifications of the nonlinear effective…
We describe how the non-local regularization can be implemented in the calculation of solitons in the Nambu Jona-Lasinio model as well as in the equivalent linear sigma-model. We investigate different forms of regulators and show that the…
This work investigates a passive vector field which is transported and stretched by a divergence-free Gaussian velocity field, delta-correlated in time and poorly correlated in space (spatially nonsmooth). Although the advection of a scalar…
Through a regularization procedure, few approximation schemes of the local time of a large class of one dimensional processes are given. We mainly consider the local time of continuous semimartingales and reversible diffusions, and the…
The method of differential regularization is applied to calculate explicitly the one-loop effective potential of a bosonized Nambu--Jona-Lasinio model consisting of scalar and pseudoscalar fields. The regularization scheme independent…
A regularization scheme that explicitly separates vacuum contributions from medium effects is applied to a Nambu--Jona-Lasinio model with diquark interactions and in $\beta-$equilibrium. We perform a comparison of this proposed scheme with…
We investigate the influence of the allowed unphysical meson decay into a quark-antiquark pair of the three flavour Nambu--Jona-Lasinio (NJL) model on its parameter fixing. This decay manifests in a non-vanishing imaginary part of the…
Nambu-Jona-Lasinio model used to investigate low energy phenomena is nonrenormalizable, therefore the results depend on the regularization parameter in general. A possibility of the finite in four-dimensional limit and even the…
In this work, we mainly study the one-loop effective action for real scalar theories in non-homogeneous backgrounds in odd dimensions. It is shown that through the method studied in Ref. [1], it is possible to obtain a unified result for…
We present results from a Monte Carlo simulation of the Nambu - Jona-Lasinio model, with continuous SU(2)xSU(2) chiral symmetry, in four Euclidean dimensions. Different model equations of state, corresponding to different theoretical…
This paper serves as a first foray on regularisation for planar vector fields. Motivated by singularities in celestial mechanics, the block regularisation of a generic class of degenerate singularities is studied. The paper is concerned…