arXiv subjects

Alexander A. Andrianov

Publications and source records attributed to Alexander A. Andrianov.

23 records · Page 2Linked to original sources

arXiv2008

Reconstruction of scalar potentials in two-field cosmological models

We study the procedure of the reconstruction of phantom-scalar field potentials in two-field cosmological models. It is shown that while in the one-field case the chosen cosmological evolution defines uniquely the form of the scalar potential, in the two-field case one has an infinite number of possibilities. The classification of a large class of possible potentials is presented and the dependence of cosmological dynamics on the choice of initial conditions is investigated qualitatively and numerically for two particular models.

gr-qc↗

arXiv2005

Phantom universe from CPT symmetric QFT

Inspired by the generalization of quantum theory for the case of non-Hermitian Hamiltonians with CPT symmetry, we construct a simple classical cosmological scalar field based model describing a smooth transition from ordinary dark energy to the phantom one.

gr-qc↗

arXiv2005

Smooth dynamical (de)-phantomization of a scalar field in simple cosmological models

Simple scalar field cosmological models are considered describing gravity assisted crossing of the phantom divide line. This crossing or (de)-phantomization characterized by the change of the sign of the kinetic term of the scalar field is smooth and driven dynamically by the Einstein equations. Different cosmological scenarios, including the phantom phase of matter are sketched.

gr-qc↗

arXiv2004

Quark-Antiquark Bound States in an Extended QCD_2 Model

We study an extended QCD model in 2D obtained from QCD in 4D by compactifying two spatial dimensions and projecting onto the zero-mode subspace. This system is found to induce a dynamical mass for transverse gluons -- adjoint scalars in QCD(2), and to undergo a chiral symmetry breaking with the full quark propagators yielding non-tachyonic, dynamical quark masses, even in the chiral limit. We construct the hadronic color singlet bound-state scattering amplitudes and study quark-antiquark bound states which can be classified in this model by their properties under Lorentz transformations inherited from 4D.

hep-th↗

arXiv2004

Extended QCD(2) from dimensional projection of QCD(4)

We study an extended QCD model in (1+1) dimensions obtained from QCD in 4D by compactifying two spatial dimensions and projecting onto the zero-mode subspace. We work out this model in the large $N_c$ limit and using light cone gauge but keeping the equal-time quantization. This system is found to induce a dynamical mass for transverse gluons -- adjoint scalars in QCD(2), and to undergo a chiral symmetry breaking with the full quark propagators yielding non-tachyonic, dynamical quark masses, even in the chiral limit. We study quark-antiquark bound states which can be classified in this model by their properties under Lorentz transformations inherited from 4D. The scalar and pseudoscalar sectors of the theory are examined and in the chiral limit a massless ground state for pseudoscalars is revealed with a wave function generalizing the so called 't Hooft pion solution.

hep-th↗