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.

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 Large N external-field quantum electrodynamics

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Felix Karbstein
Keyword(s):  
Electromagnetic Field ◽  
External Field ◽  
Effective Action ◽  
Quantum Electrodynamics ◽  
Strong Field ◽  
Loop Order ◽  
Field Limit ◽  
Effective Lagrangian ◽  
Large N ◽  
The One

Abstract We advocate the study of external-field quantum electrodynamics with N charged particle flavors. Our main focus is on the Heisenberg-Euler effective action for this theory in the large N limit which receives contributions from all loop orders. The contributions beyond one loop stem from one-particle reducible diagrams. We show that specifically in constant electromagnetic fields the latter are generated by the one-loop Heisenberg-Euler effective Lagrangian. Hence, in this case the large N Heisenberg-Euler effective action can be determined explicitly at any desired loop order. We demonstrate that further analytical insights are possible for electric-and magnetic-like field configurations characterized by the vanishing of one of the secular invariants of the electromagnetic field and work out the all-orders strong field limit of the theory.

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.

ONE-LOOP FREE ENERGY FOR D-BRANES IN CONSTANT ELECTROMAGNETIC FIELD

1996 ◽  
Vol 11 (31) ◽  
pp. 2525-2530 ◽  
Author(s):  
A.A. BYTSENKO ◽  
S.D. ODINTSOV ◽  
L.N. GRANDA
Keyword(s):  
Free Energy ◽  
Electromagnetic Field ◽  
Nonzero Temperature ◽  
Constant Electromagnetic Field ◽  
Em Field ◽  
The One

We calculate the one-loop free energy for two parallel D-branes connected by open bosonic (neutral or charged) string in a constant uniform electromagnetic (EM) field at nonzero temperature. For neutral string, external EM field contribution appears as multiplier (Born-Infeld type action) of one-loop quantities without the external EM field. The Hagedorn temperature is not changed if compare with the case of standard string gas in the constant electromagnetic field.

On the effective Lagrangian for scalar electrodynamics

1985 ◽  
Vol 63 (3) ◽  
pp. 431-434 ◽  
Author(s):  
Abul Mansur Chowdhury ◽  
Gerry McKeon
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Fields ◽  
Vector Fields ◽  
Quantum Fluctuations ◽  
External Electromagnetic Field ◽  
Second Order ◽  
Type Approximation ◽  
Effective Lagrangian ◽  
Scalar And Vector Fields ◽  
The One

The one-loop effective Lagrangian in scalar electrodynamics is computed using an expansion to second order in the external electromagnetic field and a WKB-type approximation. Quantum fluctuations of both the scalar and vector fields about background scalar and electromagnetic fields are considered.

The Influence of Recombination between Holes and Reduced Redox Ions on the Efficiency of Hole Injection from Electrolytic Contacts into Organic Insulator Crystals

1976 ◽  
Vol 31 (8) ◽  
pp. 981-986 ◽  
Author(s):  
F. Willig ◽  
G. Scherer
Keyword(s):  
Field Strength ◽  
External Field ◽  
Crystal Surface ◽  
Extreme Case ◽  
The Other ◽  
Hole Injection ◽  
The One ◽  
Suitable System ◽  
Hole Generation ◽  
Crystal Bulk

Abstract The efficiency of hole injection from electrolytic contacts into organic insulator crystals is con-trolled by hole generation and hole destruction at the crystal surface through oxidized and reduced redox ions respectively and by hole escape into the crystal bulk which competes with hole destruction. By increasing the concentration of reduced redox ions from virtually zero in a suitable system the transition has been studied from the one extreme case where all the generated holes contribute to the injection current to the other extreme case where the majority of the generated holes recombines with reduced redox ions before they can escape into the crystal bulk. From the experiments one can deduce that the generated hole spends less than 10-10 s within the reaction distance of its reduced parent redox ion, at external field strengths ≧ 104 V/cm, but returns to the crystal surface during a much longer time, e.g. during about 10-8 s at an external field strength of 105 V/cm, before it can escape finally into the crystal bulk.

scholarly journals Contributions to Born’s new theory of the electromagnetic field

1935 ◽  
Vol 150 (870) ◽  
pp. 465-477 ◽  
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Field Strength ◽  
Lagrange Function ◽  
Variation Principle ◽  
Partial Derivatives ◽  
Independent Variables ◽  
Analytic Expressions ◽  
Magnetic Vectors ◽  
Derivatives Of

Born’s theory starts from describing the field by two vectors (or a “six-vector”), B, E, the magnetic induction and electric field-strength respectively. A second pair of vectors (or a second six-vector) H, D, is introduced, merely an abbreviation, if you please, for the partial derivatives of the Lagrange function with respect to the components of B and E respectively (though with the negative sign for E). H is called magnetic field and D dielectric displacement. It was pointed out by Born that it is possible to choose the independent vectors in different ways. Four different and, to a certain extent, equivalent and symmetrical representations of the theory can be given by combining each of the two “magnetic” vectors with each of the two “electric” vectors to form the set of six independent variables. Every one of these four representations can be derived from a variation principle, using, of course, entirely different Lagrange functions—physically different, that is, though their analytic expressions by the respective variables are either identical or very similar to each other. In studying Born’s theory I came across a further representation, which is so entirely different from all the aforementioned, and presents such curious analytical aspects, that I desired to have it communicated. The idea is to use two complex combinations of B, E, H, D as independent variables, but in such a way that their “conjugates,” i. e. , the partial derivatives of L , equal their complex conjugates.

scholarly journals VACUUM POLARIZATION OF SUPERSYMMETRIC D-BRANE IN THE CONSTANT ELECTROMAGNETIC FIELD

1998 ◽  
Vol 13 (19) ◽  
pp. 1531-1537
Author(s):  
TOMOKO KADOYOSHI ◽  
AKIO SUGAMOTO ◽  
SHIN'ICHI NOJIRI ◽  
SERGEI D. ODINTSOV
Keyword(s):  
Electromagnetic Field ◽  
Effective Potential ◽  
Vacuum Polarization ◽  
Explicit Calculation ◽  
Constant Electromagnetic Field ◽  
The One

We study the vacuum polarization of supersymmetric toroidal D-brane placed in the constant electromagnetic field. Explicit calculation of the one-loop effective potential is performed for membrane with constant magnetic or electric background. We find that the one-loop potentials vanish as the effect of supersymmetry.

scholarly journals ELECTROMAGNETIC INTERACTION OF MASSIVE SPIN-3 STATE FROM STRING THEORY

2000 ◽  
Vol 15 (03) ◽  
pp. 395-411 ◽  
Author(s):  
S. M. KLISHEVICH
Keyword(s):  
Electromagnetic Field ◽  
External Field ◽  
Electromagnetic Interaction ◽  
Brst Quantization ◽  
Open String ◽  
Gauge Invariant ◽  
Constant Electromagnetic Field ◽  
Massive Spin ◽  
The Given ◽  
Mass Level

In our present work we study an interaction of second mass level of an open bosonic string with constant electromagnetic field. This state contains massive fields with spins 3 and 1. Using a method based on the BRST quantization of an open string, we obtain gauge-invariant Lagrangian, describing the electromagnetic interaction of these fields. From the explicit form of transformations and Lagrangian it follows that the presence of the external constant e.m. field induces the mixing of the states at the given level. Most likely, the presence of the external field will lead to the mixing of the states on other mass string levels as well.

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