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M. N. Chernodub

Publications and source records attributed to M. N. Chernodub.

At least 217 records · Page 12Linked to original sources
arXiv1998

Embedded Topological Defects in Electroweak Theory: From Percolating Networks to Sphalerons

New defects (Z-vortices and Nambu monopoles) are found to become thermodynamically relevant for the broken phase near to the (weakly first order) electroweak phase transition, and below the crossover for higher Higgs mass. The symmetric phase is characterized by vortex condensation (percolation). The percolation transition persists in the crossover region. The quasiclassical nature of the vortices is supported by correlations with Higgs field and gauge field energy. Sphalerons are shown to be related to monopolium bound states.

hep-lat↗
arXiv1998

Embedded Topological Defects in Hot Electroweak Theory: a Lattice Study

We study the properties of Nambu monopoles and Z-vortices in the 3D lattice SU(2) Higgs theory which represents the Standard Model at high temperature. We show that the densities of the Nambu monopoles and the Z-vortices are O(1) in the symmetric phase and generically small in the Higgs phase. Near to the critical Higgs mass and in the vicinity of the phase transition the densities are no more negligible in the broken phase. The percolation probability of the Z-vortex lines is found as a new disorder parameter for this phase transition. We conclude that the transition to the symmetric phase is accompanied by Z-vortex condensation. Simulations comparing elementary and extended vortices and monopoles at different β_G values, aiming to show that the density of vortices and monopoles of fixed physical size might have a well-defined continuum limit, gives encouraging but so far inconclusive results.

hep-lat↗
arXiv1998

Topological Content of the Electroweak Sphaleron on the Lattice

3D electroweak sphalerons on the lattice are used as test configurations for definitions of various topological defects. In the maximally Abelian gauge they are shown to contain a symmetric array of Abelian monopoles and anti-monopoles connected by two kinds of Abelian vortex strings. Gauge-invariant lattice definitions of the Nambu monopole and the Z-vortex string are formulated which correspond to Abelian projection from the unitary gauge. The sphalerons contain in their core just one (non-Abelian) Nambu monopole-anti-monopole pair (connected by a Z-string) in an unstable saddle point bound state. This provides an example for the monopole-pair unbinding mechanism expected to work at the electroweak phase transition. The definitions of defects developed here will be used in future studies of topological aspects of this transition.

hep-lat↗
arXiv1998

Strings and Aharonov-Bohm Effect in Abelian Higgs Model

We investigate numerically the properties of the Abrikosov-Nielsen-Olesen strings in 4D abelian Higgs model. The fractal dimension D_f of the vortex strings was found to be large in the Coulomb phase and it is close to 2 in the Higgs phase. We also show that the Wilson loop for non-integer charges is correlated with the linking number of the vortex string world sheets and the test particle world trajectory. We find that this topological (Aharonov-Bohm) interaction gives the main contribution to the Wilson loop quantum average for non-integer test charges in the vicinity of the Coulomb-Higgs phase transition.

hep-lat↗
arXiv1998

Vortex Dynamics in Classical Non--Abelian Spin Models

We discuss the abelian vortex dynamics in the abelian projection approach to non-abelian spin models. We show numerically that in the three-dimensional SU(2) spin model in the Maximal Abelian projection the abelian off-diagonal vortices are not responsible for the phase transition contrary to the diagonal vortices. A generalization of the abelian projection approach to SU(N) spin models is briefly discussed.

hep-lat↗
arXiv1998

Dyon Condensation and Aharonov-Bohm Effect

We derive the string representation of the Abelian Higgs theory in which dyons are condensed. It occurs that in such representation the topological interaction exists in the expectation value of the Wilson loop. Due to this interaction the dynamics of the string spanned on the Wilson loop is non-trivial.

hep-th↗
arXiv1998

Properties of Abelian Monopoles in SU(2) Lattice Gluodynamics

We discuss some properties of abelian monopoles in the Maximal Abelian projection of the SU(2) lattice gluodynamics. We show that in the maximal abelian projection abelian monopoles carry fluctuating electric charge and that the monopole currents are correlated with the magnetic and the electric parts of the SU(2) action density.

hep-lat↗
arXiv1997

Mass Gap, Abelian Dominance and Vortex Dynamics in SU(2) Spin Model

We discuss a new approach to the investigation of the nature of the mass gap in spin systems with continuous global symmetries which is much analogous to the method of abelian projection in the gauge theories. We suggest that the abelian degrees of freedom, in particular, abelian vortices are responsible for the mass gap generation phenomena in the non-abelian spin systems. To check our hypothesis we study numerically the three-dimensional SU(2) spin model in the Maximal Abelian projection. We find that the abelian mass gap in the projected theory coincides with the full non-abelian mass gap within numerical errors. The study of the percolation properties of the abelian vortex trajectories shows that the phase transition and the mass gap generation in the 3D SU(2) spin model are driven by the abelian vortex condensation.

hep-lat↗
arXiv1997

Abelian Projections and Monopoles

The monopole confinement mechanism in the abelian projection of lattice gluodynamics is reviewed. The main topics are: the abelian projection on the lattice and in the continuum, a numerical study of the abelian monopoles in the lattice gauge theory. Additionally, we briefly review the notation of differential forms, duality, and the BKT transformation in the lattice gauge theories.

hep-th↗
arXiv1997

Aharonov-Bohm Effect in Lattice Abelian Higgs Theory

We study a field-theoretical analogue of the Aharonov-Bohm effect in two-, three- and four-dimensional Abelian Higgs models; the corresponding topological interaction is proportional to the linking number of the Abrikosov vortex and the particle world trajectories. We show that the Aharonov-Bohm effect gives rise to a nontrivial interaction of charged test particles. The numerical calculations in the three-dimensional model confirm this fact.

hep-lat↗
arXiv1997

Abelian Monopoles in SU(2) Lattice Gauge Theory as Physical Objects

By numerical calculations we show that the abelian monopole currents are locally correlated with the density of SU(2) lattice action. The correlations are larger by the order of magnitude in the maximal abelian projection than in the projections which correspond to the diagonalization of Polyakov line and to the diagonalization of the plaquette. These facts show that (at least) in the maximal abelian projection the monopoles are the physical objects, they carry the SU(2) action. The larger value of β, the larger the relative action carried by monopole. Calculations on the asymmetric lattice show that this correlation exists also in the deconfinement phase of gluodynamics.

hep-lat↗
arXiv1997

Various representations of infrared effective lattice QCD

We study various representations of the infrared effective theory of SU(2) gluodynamics starting from the monopole action derived recently. We determine the coupling constants in the abelian-Higgs model directly from lattice QCD and evaluate the type of the QCD vacuum. The string action is derived using the BKT transformation on the lattice. At the classical level this action reproduces the physical string tension with a good accuracy.

hep-lat↗
arXiv1997

Abelian monopoles in lattice gluodynamics as physical objects

By numerical calculations we show that the abelian monopole currents are locally correlated with the density of SU(2) lattice action. This fact is established for the maximal abelian projection. Thus, in the maximal abelian projection the monopoles are physical objects, they carry SU(2) action. Calculations on the asymmetric lattice show that the correlation between monopole currents and the density of SU(2) lattice action also exists in the deconfinement phase of gluodynamics.

hep-lat↗
arXiv1997

Electric and magnetic currents in SU(2) lattice gauge theory

The correlations of the topological charge (Q), the electric (Je) and the magnetic (Jm) currents in the SU(2) lattice gauge theory in the Maximal Abelian projection are investigated. A nonzero value of the correlator is obtained for a wide range of values of the bare charge, as well as under the cooling.

hep-lat↗
arXiv1997

Abelian Projection of SU(2) Gluodynamics and Monopole Condensate

The general properties of the abelian projection are reviewed. We derive the explicit expression for the abelian functional integral for U(1) abelian theory which corresponds to the abelian projection of the SU(2) gluodynamics. The numerical results for the temperature dependence of the monopole condensate are presented.

hep-th↗
arXiv1997

Effective Constraint Potential for Abelian Monopole in SU(2) Lattice Gauge Theory

We describe numerical calculation results for the probability distribution of the value of the monopole creation operator in the SU(2) lattice gluodynamics. We work in the maximal abelian projection. It occurs that at low temperatures, below the deconfinement phase transition, the maximum of the distribution is shifted from zero, which means that the effective constraint potential is of the Higgs type. Above the phase transition the minimum of the potential (the maximum of the monopole field distribution) is at the zero value of the monopole field. This fact confirms the existence of the abelian monopole condensate in the confinement phase of lattice gluodynamics, and agrees with the dual superconductor model of the confining vacuum.

hep-lat↗
arXiv1996

Aharonov--Bohm Effect in 3D Abelian Higgs Theory

We study a field--theoretical analogue of the Aharonov--Bohm effect in the 3D Abelian Higgs Model: the corresponding topological interaction is proportional to the linking number of the vortex and the particle world trajectories. We show that the Aharonov--Bohm effect gives rise to a nontrivial interaction of tested charged particles.

hep-lat↗