scholarly journals Schwarzian derivative treatment of the quantum second-order supersymmetry anomaly, and coupling-constant metamorphosis

2017 ◽  
Vol 377 ◽  
pp. 164-179 ◽  
Author(s):  
Mikhail S. Plyushchay
Keyword(s):  
Schwarzian Derivative ◽  
Second Order ◽  
Coupling Constant

scholarly journals SECOND-ORDER CORRECTIONS TO QED COUPLING AT LOW TEMPERATURE

2008 ◽  
Vol 23 (29) ◽  
pp. 4709-4719 ◽  
Author(s):  
SAMINA S. MASOOD ◽  
MAHNAZ HASEEB
Keyword(s):  
Low Temperatures ◽  
Vacuum Polarization ◽  
Second Order ◽  
Electromagnetic Properties ◽  
Electron Mass ◽  
Polarization Tensor ◽  
Coupling Constant ◽  
Electric Permittivity ◽  
Thermal Medium ◽  
Vacuum Polarization Tensor

We calculate the second-order corrections to vacuum polarization tensor of photons at low temperatures, i.e. T ≪ 1010 K (T ≪ me). The thermal contributions to the QED coupling constant are evaluated at temperatures below the electron mass that is T < me. Renormalization of QED at these temperatures has explicitly been checked. The electromagnetic properties of such a thermal medium are modified. Parameters like electric permittivity and magnetic permeability of such a medium are no more constant and become functions of temperature.

On the Convergence of the Calculated Spin-spin Coupling Constant of HD

1979 ◽  
Vol 34 (10) ◽  
pp. 1158-1159
Author(s):  
H. P. Trivedi
Keyword(s):  
Cross Coupling ◽  
Second Order ◽  
The Self ◽  
Spin Coupling ◽  
Coupling Constant ◽  
Spin Coupling Constant ◽  
Coupling Energy ◽  
Order Energy ◽  
The Cross ◽  
Spin Spin Coupling

Abstract It is shown that the concurrence of the results obtained by varying the self coupling energy, the total second order energy and the cross coupling energy independently can be readily accomplished. In addition, it is possible to arrange to obtain any pre-specified value for the coupling constant. On this basis it is suggested that it might be dangerous to construe the concurrence of calculated results as an indication of convergence in practice.

Spin–orbit splitting in 2Δ states of diatomic molecules

1969 ◽  
Vol 47 (23) ◽  
pp. 2727-2730 ◽  
Author(s):  
H. Lefebvre-Brion ◽  
N. Bessis
Keyword(s):  
Diatomic Molecules ◽  
Orbit Interaction ◽  
Second Order ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupling Constant ◽  
Orbit Splitting ◽  
Spin Orbit Splitting ◽  
Good Agreement

The origin of the splitting of the 2Δ states arising from the σπ2 configuration is studied. For light diatomic molecules, the splitting is shown to arise from the spin–other–orbit interaction which gives a small negative value for the spin–orbit coupling constant A. Non-empirical calculations of A for the 2Δ states of the CH, NH+, and NO molecules are in good agreement with experiment. In heavier molecules, the spin–other–orbit interaction becomes negligible and the second-order spin–orbit effect is dominant.

scholarly journals Integration of second order linear differential equations in elementary functions, example from quantum-mechanics

2018 ◽  
Vol 251 ◽  
pp. 04015
Author(s):  
Alexander Chichurin ◽  
Viktor Red’kov
Keyword(s):  
Differential Equation ◽  
Schwarzian Derivative ◽  
Second Order ◽  
Quantum Mechanical ◽  
Order Linear Differential Equation ◽  
Elementary Functions ◽  
Mechanical Problem ◽  
Order Linear ◽  
Special Procedure ◽  
Linear Differential

In the paper, special procedure for integrating a second order linear differential equation with six singular points, example of a quantum-mechanical problem for a spin zero particle with intrinsic Darwin—Cox structure, is considered. The method is based on the use of the Schwarzian derivative, conditions for parameters are derived at which solutions of the equation under consideration are constructed in terms of elementary functions. The graphs for several solutions are presented, their physical sense is discussed.

scholarly journals CONSISTENT INTERACTIONS BETWEEN GAUGE FIELDS AND LOCAL BRST COHOMOLOGY: THE EXAMPLE OF YANG-MILLS MODELS

1994 ◽  
Vol 03 (01) ◽  
pp. 139-144 ◽  
Author(s):  
G. BARNICH ◽  
M. HENNEAUX ◽  
R. TATAR
Keyword(s):  
Vector Fields ◽  
Jacobi Identity ◽  
Second Order ◽  
Gauge Fields ◽  
Coupling Constant ◽  
Yang Mills ◽  
First Order ◽  
Gauge Symmetries ◽  
Brst Cohomology ◽  
Structure Constants

Recent results on the cohomological reformulation of the problem of consistent interactions between gauge fields are illustrated in the case of the Yang-Mills models. By evaluating the local BRST cohomology through descent equation techniques, it is shown (i) that there is a unique local, Poincaré invariant cubic vertex for free gauge vector fields which preserves the number of gauge symmetries to first order in the coupling constant; and (ii) that consistency to second order in the coupling constant requires the structure constants appearing in the cubic vertex to fulfill the Jacobi identity. The known uniqueness of the Yang-Mills coupling is therefore rederived through cohomological arguments.

scholarly journals THREE-LOOP CALCULATION OF THE ANYONIC FULL CLUSTER EXPANSION

1993 ◽  
Vol 08 (34) ◽  
pp. 3291-3299 ◽  
Author(s):  
R. EMPARAN ◽  
M.A. VALLE BASAGOITI
Keyword(s):  
Field Theory ◽  
Cluster Expansion ◽  
Cluster Coefficient ◽  
Second Order ◽  
Coupling Constant ◽  
Perturbative Correction ◽  
Chern Simons

We calculate the perturbative correction to every cluster coefficient of a gas of anyons through second order in the anyon coupling constant, as described by Chern-Simons field theory.

BOUND POLARON IN A QUANTUM WELL UNDER THE INFLUENCE OF AN ELECTRIC FIELD

2006 ◽  
Vol 20 (21) ◽  
pp. 3049-3055 ◽  
Author(s):  
A. JOHN PETER
Keyword(s):  
Perturbation Theory ◽  
Electric Field ◽  
Quantum Well ◽  
Second Order ◽  
Binding Energies ◽  
Order Perturbation ◽  
Order Perturbation Theory ◽  
Coupling Constant ◽  
Lattice Coupling ◽  
Second Order Perturbation Theory

Polaronic shifts of the donor binding energies in an electric field in a quantum well are presented here. The properties of a polaron in a quantum well are investigated within the second-order perturbation theory. GaAs / Ga 1-x Al x As quantum well is chosen as an example to calculate the polaron energy. Since this system is a weak polar material, the electron-lattice coupling constant is small so this effect is considered by second-order perturbation theory. The polaronic effects are suppressed when an electric field is coupled. The diamagnetic susceptibility is also calculated and the results are compared with the results obtained using other approximation methods.

scholarly journals Perturbative linearization of supersymmetric Yang-Mills theory

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Sudarshan Ananth ◽  
Olaf Lechtenfeld ◽  
Hannes Malcha ◽  
Hermann Nicolai ◽  
Chetan Pandey ◽  
...  
Keyword(s):  
Gauge Theories ◽  
Second Order ◽  
Coupling Constant ◽  
Supersymmetric Gauge Theories ◽  
Third Order ◽  
Yang Mills ◽  
Fresh Perspective ◽  
Supersymmetric Gauge ◽  
Jacobi Determinant

Abstract Supersymmetric gauge theories are characterized by the existence of a transformation of the bosonic fields (Nicolai map) such that the Jacobi determinant of the transformation equals the product of the Matthews-Salam-Seiler and Faddeev-Popov determinants. This transformation had been worked out to second order in the coupling constant. In this paper, we extend this result (and the framework itself ) to third order in the coupling constant. A diagrammatic approach in terms of tree diagrams, aiming to extend this map to arbitrary orders, is outlined. This formalism bypasses entirely the use of anti-commuting variables, as well as issues concerning the (non-)existence of off-shell formulations for these theories. It thus offers a fresh perspective on supersymmetric gauge theories and, in particular, the ubiquitous $$ \mathcal{N} $$ N = 4 theory.

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