Modern Physics Letters A

The technique of one-loop calculations for the processes involving Reggeized quarks is described in the framework of gauge invariant effective field theory for the Multi-Regge limit of QCD, which has been introduced by Lipatov and Vyazovsky. The rapidity divergences, associated with the terms enhanced by log(s), appear in the loop corrections in this formalism. The covariant procedure of regularization of rapidity divergences, preserving the gauge invariance of effective action is described. As an example application, the one-loop correction to the propagator of Reggeized quark and $\gamma Qq$-scattering vertex are computed. Obtained results are used to construct the Regge limit of one-loop $\gamma \gamma \to q\bar{q}$ amplitude. The cancellation of rapidity divergences and consistency of the EFT prediction with the full QCD result is demonstrated. The rapidity renormalization group within the EFT is discussed.

Spectral line widths, the Lamb shift and the Casimir effect are generally accepted to be observable consequences of the zero-point electromagnetic (ZPEM) fields. A new class of observable consequences of ZPEM field at the mesoscopic scale were recently proposed and observed. Here, we extend this class of observable effects and predict that mesoscopic water layers should have a high value for its solid–liquid phase transition temperature, as illustrated by water inside a single-walled carbon nanotube (CNT). For this case, our analysis predicts that the phase transition temperature scales inversely with the square of the effective radius available for the water flow within the CNT.

In this work, a model for the pre-inflationary universe is developed where the sources of the gravitational field are a relativistic fluid and a self-interacting fermionic field. The inclusion of the relativistic fluid is based on Schutz’s model. From the classical analysis based on the Hamiltonian formalism, it is shown that the fluid degrees of freedom can be embodied by a conformal time variable and an expression for the scale factor as function of the conformal time is obtained. From the Wheeler–DeWitt equation, the expected value for the scale factor as function of the conformal time is determined. It is shown that contrary to the classical solution, the expected value of the scale factor does not have a singularity, since it is preceded by a contracted phase up to a minimum value from which the universe begins to expand. Furthermore, from the plots of the classical and quantum solutions for the scale factor as functions of the conformal time it is shown that a decoherence of the quantum solution occurs for late times and both solutions coincide.

We consider the most general renormalizable theory of propagating torsion in Einstein gravity for the Dirac matter distribution and we demonstrate that in this case, torsion is a massive axial-vector field whose coupling to the spinor gives rise to conditions in terms of which gravitational singularities are not bound to form; we discuss how our results improve those that are presented in the existing literature, and that no further improvement can be achieved unless one is ready to re-evaluate some considerations on the renormalizability of the theory.

Three representations of Nambu–Jona-Lasinio interaction Lagrangians are constructed by Fierz transformation, and gap equation and critical end point in these three representations at finite temperature and finite chemical potential are studied. We find that the values of the quark mass and the critical end point are different in these three representations because of the consideration of Hartree–Fock approximation in our calculation.

The geodesics on the (1 + 3)-dimensional de Sitter (dS) spacetime are considered studying how their parameters are determined by the conserved quantities in the conformal Euclidean, Friedmann–Lemaître–Robertson–Walker, de Sitter–Painlevé and static local charts with Cartesian space coordinates. Moreover, it is shown that there exists a special static chart in which the geodesics are genuine hyperbolas whose asymptotes are given by the conserved momentum and the associated dual momentum.

We recently formulated a model of the universe based on an underlying W3-symmetry. It allows the creation of the universe from nothing and the creation of baby universes and wormholes for spacetimes of dimension 2, 3, 4, 6 and 10. Here we show that the classical large time and large space limit of these universes is one of exponential fast expansion without the need of a cosmological constant. Under a number of simplifying assumptions, our model predicts that w = −1.2 in the case of four-dimensional spacetime. The possibility of obtaining a w-value less than −1 is linked to the ability of our model to create baby universes and wormholes.