In-out formalism for the QED effective action in a constant electromagnetic field

2012 ◽  
Vol 61 (8) ◽  
pp. 1206-1214 ◽  
Author(s):  
Sang Pyo Kim
Keyword(s):  
Electromagnetic Field ◽  
Effective Action ◽  
Constant Electromagnetic Field

scholarly journals EULER–HEISENBERG LAGRANGIAN THROUGH KREIN REGULARIZATION

2013 ◽  
Vol 28 (14) ◽  
pp. 1350056 ◽  
Author(s):  
A. REFAEI
Keyword(s):  
Electromagnetic Field ◽  
Effective Action ◽  
Light Cone ◽  
Krein Space ◽  
Renormalization Procedure ◽  
Constant Electromagnetic Field ◽  
Kreĭn Space ◽  
The One ◽  
Convergent Solution ◽  
Krein Regularization

The Euler–Heisenberg effective action at the one-loop for a constant electromagnetic field is derived in Krein space quantization with Ford's idea of fluctuated light-cone. In this work, we present a perturbative but convergent solution of the effective action. Without using any renormalization procedure, the result coincides with the famous renormalized Euler–Heisenberg action.

scholarly journals ANALYTIC RESULTS FOR THE EFFECTIVE ACTION

1991 ◽  
Vol 06 (30) ◽  
pp. 5409-5433 ◽  
Author(s):  
STEVEN K. BLAU ◽  
MATT VISSER ◽  
ANDREAS WIPF
Keyword(s):  
Electromagnetic Field ◽  
Asymptotic Expansion ◽  
Zeta Function ◽  
Effective Action ◽  
Strong Field ◽  
Weak Field ◽  
Four Dimensions ◽  
Effective Lagrangian ◽  
Constant Electromagnetic Field ◽  
The One

Motivated by the seminal work of Schwinger, we obtain explicit closed-form expressions for the one-loop effective action in a constant electromagnetic field. We discuss both massive and massless charged scalars and spinors in two, three and four dimensions. Both strong-field and weak-field limits are calculable. The latter limit results in an asymptotic expansion whose first term reproduces the Euler-Heinsenberg effective Lagrangian. We use the prescription of zeta-function renormalization, and indicate its relationship to Schwinger’s renormalized effective action.

scholarly journals Quantum Scalar Field in the FRW Universe with a Constant Electromagnetic Background

1997 ◽  
Vol 12 (27) ◽  
pp. 4837-4867 ◽  
Author(s):  
S. P. Gavrilov ◽  
D. M. Gitman ◽  
S. D. Odintsov
Keyword(s):  
Electromagnetic Field ◽  
Scalar Field ◽  
Effective Action ◽  
Proper Time ◽  
Back Reaction ◽  
De Sitter ◽  
Frw Universe ◽  
Massive Scalar Field ◽  
Mean Values ◽  
Constant Electromagnetic Field

We discuss a massive scalar field with conformal coupling in the Friedmann–Robertson–Walker (FRW) Universe of a special type with a constant electromagnetic field. Treating an external gravitational–electromagnetic background exactly, at the first time the proper-time representations for out–in, in–in and out–out scalar Green functions are explicitly constructed as proper-time integrals over the corresponding (complex) contours. The vacuum-to-vacuum transition amplitudes and the number of created particles are found and vacuum instability is discussed. The mean values of the current and the energy–momentum tensor are evaluated, and different approximations for them are investigated. The back reaction of the particles created to the electromagnetic field is estimated in different regimes. The connection between the proper-time method and the effective action is outlined. The effective action in scalar QED in the weakly curved FRW Universe (de Sitter space) with a weak constant electromagnetic field is found as a derivative expansion over curvature and electromagnetic field strength. Possible further applications of the results are mentioned.

scholarly journals VACUUM POLARIZATION IN QED WITH WORLD-LINE METHODS

2002 ◽  
Vol 17 (06n07) ◽  
pp. 960-965
Author(s):  
R. SHAISULTANOV
Keyword(s):  
Electromagnetic Field ◽  
Effective Action ◽  
Arbitrary Constant ◽  
Vacuum Polarization ◽  
World Line ◽  
Field Configuration ◽  
Constant Electromagnetic Field

The application of world-line techniques to calculation of the vacuum polarization and effective action in scalar and spinor QED with external arbitrary constant electromagnetic field configuration is presented.

scholarly journals Derivative expansion for the one-loop effective Lagrangian in QED

1996 ◽  
Vol 74 (5-6) ◽  
pp. 282-289 ◽  
Author(s):  
V. P. Gusynin ◽  
I. A. Shovkovy
Keyword(s):  
Electromagnetic Field ◽  
Field Strength ◽  
External Field ◽  
Explicit Expression ◽  
Derivative Expansion ◽  
Effective Lagrangian ◽  
Constant Electromagnetic Field ◽  
The One ◽  
Derivatives Of

The derivative expansion of the one-loop effective Lagrangian in QED4 is considered. The first term in such an expansion is the famous Schwinger result for a constant electromagnetic field. In this paper we give an explicit expression for the next term containing two derivatives of the field strength Fμν. The results are presented for both fermion and scalar electrodynamics. Some possible applications of an inhomogeneous external field are pointed out.

Semiclassical Form of the Relativistic Particle Propagator

1997 ◽  
Vol 12 (32) ◽  
pp. 2435-2443
Author(s):  
Dmitri M. Gitman ◽  
Stoian I. Zlatev
Keyword(s):  
Electromagnetic Field ◽  
Relativistic Particle ◽  
External Electromagnetic Field ◽  
Path Integral Representation ◽  
Constant Electromagnetic Field ◽  
Final Formula ◽  
Nonrelativistic Quantum Mechanics ◽  
Van Vleck ◽  
Detailed Derivation ◽  
Particle Propagator

A detailed derivation of the semiclassical form for the relativistic particle propagator in arbitrary external electromagnetic field is presented. To this end a path-integral representation is used. The final formula is a generalization of the Van Vleck–Pauli–Morette semiclassical representation in the nonrelativistic quantum mechanics. We demonstrate the efficiency of the former in the case of an arbitrary constant electromagnetic field.

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