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 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 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.

Effective Actions in QED in 1+1, 2+1 and 3+1 Dimensions

1997 ◽  
Vol 12 (06) ◽  
pp. 1153-1160 ◽  
Author(s):  
M. P. Fry
Keyword(s):  
Magnetic Fields ◽  
Effective Action ◽  
Quantum Electrodynamics ◽  
Strong Field ◽  
Static Magnetic Fields ◽  
Field Behavior ◽  
The One

Bounds on the one-loop effective action in quantum electrodynamics in 1+1, 2+1 and 3+1 dimensions are reviewed. These results are extended to include the exact strong field behavior of the effective action in four-dimensional QED for finite-flux, unidirectional, static magnetic fields that do not change sign.

scholarly journals Radiative corrections in 2 + 1 dimensional supergravity

2018 ◽  
Vol 96 (12) ◽  
pp. 1409-1412 ◽  
Author(s):  
D.G.C. McKeon
Keyword(s):  
Gauge Theory ◽  
Radiative Correction ◽  
Effective Action ◽  
Spin Connection ◽  
Dynamical Generation ◽  
Effective Lagrangian ◽  
Majorana Spinor ◽  
The One ◽  
Brst Invariance ◽  
Topological Mass

Supergravity in 2 + 1 dimensions has a set of first-class constraints that result in two bosonic and one fermionic gauge invariances. When one uses Faddeev–Popov quantization, these gauge invariances result in four fermionic scalar ghosts and two bosonic Majorana spinor ghosts. The BRST invariance of the effective Lagrangian is found. As an example of a radiative correction, we compute the phase of the one-loop effective action in the presence of a background spin connection, and show that it vanishes. This indicates that unlike a spinor coupled to a gauge field in 2 + 1 dimensions, there is no dynamical generation of a topological mass in this model. An additional example of how a BRST invariant effective action can arise in a gauge theory is provided in Appendix B where the BRST effective action for the classical Palatini action in 1 + 1 dimensions is examined.

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.

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.

scholarly journals Effective Lagrangian and Static Black Holes in 2-D Dilatonic Gravity Inspired by Quantum Effects

1997 ◽  
Vol 12 (13) ◽  
pp. 925-935 ◽  
Author(s):  
Shin'ichi Nojiri ◽  
Sergei D. Odintsov
Keyword(s):  
Black Holes ◽  
Quantum Gravity ◽  
Effective Action ◽  
Hawking Radiation ◽  
Quantum Effects ◽  
Dilaton Gravity ◽  
Effective Lagrangian ◽  
The One

We study the effective action in 2-D dilaton-Maxwell quantum gravity. Working with the one-loop renormalizable subset of such theories, we construct the improved effective Lagrangian which contains curvature under logarithm. This effective Lagrangian leads to new classical dilatonic gravity inspired by quantum effects. The static black holes (BH) solutions which may play the role of a remnant after the Hawking radiation for such theory are carefully investigated. The effective Lagrangian for Gross–Neveu-dilaton gravity is also constructed (in 1/N expansion).

CREATION OF A WORMHOLE DUE TO NONLINEAR ELECTRODYNAMICS

2002 ◽  
Vol 17 (20) ◽  
pp. 1305-1314 ◽  
Author(s):  
CARLA FONSECA-BARBATTI ◽  
M. NOVELLO ◽  
J. M. SALIM ◽  
REGINA C. ARCURI
Keyword(s):  
Magnetic Field ◽  
Quantum Electrodynamics ◽  
Nonlinear Electrodynamics ◽  
Einstein Field Equations ◽  
Field Equations ◽  
New Class ◽  
Effective Lagrangian ◽  
The One

We obtain a new class of solutions for the Einstein field equations which describe wormholes by using the one-loop effective Lagrangian of quantum electrodynamics. We also show that the derived wormholes can be maintained only by means of a magnetic field.

FERMION INDUCED SINGULARITIES IN A NON-RELATIVISTIC EFFECTIVE LAGRANGIAN FOR ELECTROMAGNETISM

1991 ◽  
Vol 05 (09) ◽  
pp. 1419-1436 ◽  
Author(s):  
S. RANDJBAR-DAEMI ◽  
ABDUS SALAM ◽  
J. STRATHDEE
Keyword(s):  
Quantum Electrodynamics ◽  
Relativistic Quantum ◽  
Effective Field ◽  
Landau Levels ◽  
Zero Temperature ◽  
Oscillatory Behaviour ◽  
Simple Derivation ◽  
Effective Lagrangian ◽  
The One ◽  
Background Fields

Effective field theory methods are applied to the study of non-relativistic quantum electrodynamics in a slowly varying electromagnetic background. It is shown that the one-loop effective action has singularities at those values of the background fields which correspond to complete fillings of Landau levels. One immediate result of our work is a simple derivation of the oscillatory behaviour of the energy density magnetization and permittivities, at zero temperature.

Sign in / Sign up

Export Citation Format

Share Document