The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
F.a. Lunev - One of the best experts on this subject based on the ideXlab platform.
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Pure bosonic world-line Path Integral Representation for fermionic determinants, non-Abelian Stokes theorem, and quasiclassical approximation in QCD
Nuclear Physics B, 1997Co-Authors: F.a. LunevAbstract:Simple bosonic Path Integral Representation for Path ordered exponent is derived. This Representation is used, at first, to obtain new variant of non-Abelian Stokes theorem. Then new pure bosonic worldline Path Integral Representations for fermionic determinant and Green functions are presented. Finally, applying stationary phase method, we get quasiclassical equations of motion in QCD.Comment: LaTeX, 49 page
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pure bosonic world line Path Integral Representation for fermionic determinants non abelian stokes theorem and quasiclassical approximation in qcd
Nuclear Physics, 1997Co-Authors: F.a. LunevAbstract:Abstract A simple bosonic Path Integral Representation for the Path ordered exponent is derived. This Representation is used, first, to obtain a new variant of the non-Abelian Stokes theorem. Then new pure bosonic world-line Path Integral Representations for the fermionic determinant and Green functions are presented. Finally, applying the stationary phase method, we get the quasiclassical equations of motion in QCD.
I Roditi - One of the best experts on this subject based on the ideXlab platform.
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dual Path Integral Representation for finite temperature quantum field theory
Physical Review D, 2008Co-Authors: Ccapa C Ttira, C D Fosco, A P C Malbouisson, I RoditiAbstract:We impose the periodicity conditions corresponding to the Matsubara formalism for thermal field theory as constraints in the imaginary-time Path Integral. These constraints are introduced by means of time-independent auxiliary fields which, by integration of the original variables, become dynamical fields in the resulting 'dual' Representation for the theory. This alternative Representation has the appealing property of involving fields that live in one dimension less than the original ones, with a quantum partition function whose integration measure is identical to the one of its classical counterpart, albeit with a different (spatially nonlocal) action.
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a new Path Integral Representation for the thermal partition function
arXiv: High Energy Physics - Theory, 2007Co-Authors: C D Fosco, A P C Malbouisson, I RoditiAbstract:The boundary conditions corresponding to the Matsubara formalism for the $T > 0$ partition function may be introduced as {\em constraints} in the Path Integral for the vacuum amplitude. We implement those constraints with time-independent Lagrange multipliers and, by integrating out the original fields, we obtain an alternative Representation for the partition function, in terms of the Lagrange multipliers as dynamical fields. The resulting functional Integral has the appealing property of involving only $d$-dimensional, {\em time independent} fields, and looks like a nonlocal version of the classical partition function. We develop this formalism within the context of the scalar and Dirac fields.
D M Gitman - One of the best experts on this subject based on the ideXlab platform.
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spin factor in the Path Integral Representation for the dirac propagator in external fields
Physical Review D, 1997Co-Authors: D M Gitman, Stoian I ZlatevAbstract:We study the problem of the spin factor both in 3+1 and 2+1 dimensions, two cases which are essentially different in this respect. Doing all Grassmann integrations in the corresponding Path Integral Representations for the Dirac propagator we get Representations with a spin factor in an arbitrary external field. Thus, the propagator appears to be presented by means of a bosonic Path Integral only. Then we use the Representations with a spin factor for calculations of the propagator in some configurations of external fields: namely, in a constant uniform electromagnetic field and in its combination with a plane wave field. {copyright} {ital 1997} {ital The American Physical Society}
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Path Integral Representation for the relativistic particle propagators and bfv quantization
Physical Review D, 1991Co-Authors: Efim S Fradkin, D M GitmanAbstract:The Path-Integral Representations for the propagators of scalar and spinor fields in an external electromagnetic field are derived. The Hamiltonian form of such expressions can be interpreted in the sense of Batalin-Fradkin-Vilkovisky quantization of one-particle theory. The Lagrangian Representation as derived allows one to extract in a natural way the expressions for the corresponding gauge-invariant (reparametrization- and supergauge-invariant) actions for pointlike scalar and spinning particles. At the same time, the measure and ranges of integrations, admissible gauge conditions, and boundary conditions can be exactly established.
Martin Zach - One of the best experts on this subject based on the ideXlab platform.
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Path Integral Representation for wilson loops and the non abelian stokes theorem
Physical Review D, 2000Co-Authors: M Faber, A N Ivanov, N I Troitskaya, Martin ZachAbstract:We discuss the derivation of the Path Integral Representation over gauge degrees of freedom for Wilson loops in $\mathrm{SU}(N)$ gauge theory and 4-dimensional Euclidean space-time by using well-known properties of group characters. A discretized form of the Path Integral is naturally provided by the properties of group characters and does not need any artificial regularization. We show that the Path Integral over gauge degrees of freedom for Wilson loops derived by Diakonov and Petrov [Phys. Lett. B 224 131 (1989)] by using a special regularization is erroneous and predicts zero for the Wilson loop. This property is obtained by direct evaluation of Path Integrals for Wilson loops defined for pure $\mathrm{SU}(2)$ gauge fields and $Z(2)$ center vortices with spatial azimuthal symmetry. Further we show that both derivations given by Diakonov and Petrov for their regularized Path Integral, if done correctly, predict also zero for Wilson loops. Therefore, the application of their Path Integral Representation of Wilson loops cannot give a new way to check confinement in lattice as has been declared by Diakonov and Petrov [Phys. Lett. B 242 425 (1990)]. From the Path Integral Representation which we consider we conclude that no new non-Abelian Stokes theorem can exist for Wilson loops except the old-fashioned one derived by means of the Path-ordering procedure.
C D Fosco - One of the best experts on this subject based on the ideXlab platform.
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dual Path Integral Representation for finite temperature quantum field theory
Physical Review D, 2008Co-Authors: Ccapa C Ttira, C D Fosco, A P C Malbouisson, I RoditiAbstract:We impose the periodicity conditions corresponding to the Matsubara formalism for thermal field theory as constraints in the imaginary-time Path Integral. These constraints are introduced by means of time-independent auxiliary fields which, by integration of the original variables, become dynamical fields in the resulting 'dual' Representation for the theory. This alternative Representation has the appealing property of involving fields that live in one dimension less than the original ones, with a quantum partition function whose integration measure is identical to the one of its classical counterpart, albeit with a different (spatially nonlocal) action.
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a new Path Integral Representation for the thermal partition function
arXiv: High Energy Physics - Theory, 2007Co-Authors: C D Fosco, A P C Malbouisson, I RoditiAbstract:The boundary conditions corresponding to the Matsubara formalism for the $T > 0$ partition function may be introduced as {\em constraints} in the Path Integral for the vacuum amplitude. We implement those constraints with time-independent Lagrange multipliers and, by integrating out the original fields, we obtain an alternative Representation for the partition function, in terms of the Lagrange multipliers as dynamical fields. The resulting functional Integral has the appealing property of involving only $d$-dimensional, {\em time independent} fields, and looks like a nonlocal version of the classical partition function. We develop this formalism within the context of the scalar and Dirac fields.
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tests and applications of migdal s particle Path Integral Representation for the dirac propagator
Physical Review D, 2004Co-Authors: C D Fosco, J Sanchezguillen, R A VazquezAbstract:We derive some nonperturbative results in $1+1$ and $2+1$ dimensions within the context of the particle Path-Integral Representation for a Dirac field propagator in the presence of an external field, in a formulation introduced by Migdal. We consider the specific properties of the Path-Integral expressions corresponding to the $(1+1)$- and $(2+1)$-dimensional cases, presenting a derivation of the chiral anomaly in the former and of the Chern-Simons current in the latter. We also discuss particle propagation in constant electromagnetic field backgrounds.