PERTURBATION THEORY IN THE WESS–ZUMINO–NOVIKOV–WITTEN MODEL

1992 ◽  
Vol 07 (04) ◽  
pp. 795-841 ◽  
Author(s):  
H. LEUTWYLER ◽  
M. SHIFMAN
Keyword(s):  
Perturbation Theory ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Two Dimensions ◽  
Perturbative Approach ◽  
Generating Functional ◽  
Wznw Model

The perturbation theory of the WZNW model in two dimensions is investigated. We obtain closed expressions for the generating functional of the chiral currents and of the energy–momentum tensor, valid to all orders in 1/k where k is the integer parameter of the model. It is demonstrated how the relations of the Kač–Moody and Virasoro algebras emerge within the perturbative approach.

scholarly journals CANONICAL APPROACH TO 2D SUPERSYMMETRIC WZNW MODEL COUPLED TO SUPERGRAVITY

2002 ◽  
Vol 17 (29) ◽  
pp. 1923-1936 ◽  
Author(s):  
OLIVERA MIŠKOVIĆ ◽  
BRANISLAV SAZDOVIĆ
Keyword(s):  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Moody Algebra ◽  
Gauge Transformations ◽  
Local Gauge ◽  
Gauge Symmetries ◽  
Wznw Model ◽  
Canonical Approach ◽  
Explicit Expressions

Starting from the known representation of the Kac–Moody algebra in terms of the coordinates and momenta, we extend it to the representation of the super Kac–Moody and super Virasoro algebras. Then we use general canonical method to construct an action invariant under local gauge symmetries, where components of the super energy–momentum tensor L± and G± play the role of the diffeomorphisms and supersymmetry generators respectively. We obtain covariant extension of WZNW theory with respect to local supersymmetry as well as explicit expressions for gauge transformations.

scholarly journals Nucleon’s energy–momentum tensor form factors in light-cone QCD

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
K. Azizi ◽  
U. Özdem
Keyword(s):  
Perturbation Theory ◽  
Lattice Qcd ◽  
Chiral Perturbation Theory ◽  
Light Cone ◽  
Energy Momentum Tensor ◽  
Form Factors ◽  
Momentum Tensor ◽  
Tensor Form ◽  
Chiral Perturbation ◽  
Theoretical Predictions

Abstract We use the energy–momentum tensor (EMT) current to compute the EMT form factors of the nucleon in the framework of the light cone QCD sum rule formalism. In the calculations, we employ the most general form of the nucleon’s interpolating field and use the distribution amplitudes (DAs) of the nucleon with two sets of the numerical values of the main input parameters entering the expressions of the DAs. The directly obtained results from the sum rules for the form factors are reliable at $$ Q^2\ge 1$$Q2≥1 GeV$$^2 $$2: to extrapolate the results to include the zero momentum transfer squared with the aim of estimation of the related static physical quantities, we use some fit functions for the form factors. The numerical computations show that the energy–momentum tensor form factors of the nucleon can be well fitted to the multipole fit form. We compare the results obtained for the form factors at $$ Q^2=0 $$Q2=0 with the existing theoretical predictions as well as experimental data on the gravitational form factor d$$_1^q(0)$$1q(0). For the form factors M$$_2^q (0)$$2q(0) and J$$^q(0)$$q(0) a consistency among the theoretical predictions is seen within the errors: our results are nicely consistent with the Lattice QCD and chiral perturbation theory predictions. However, there are large discrepancies among the theoretical predictions on d$$_1^q(0)$$1q(0). Nevertheless, our prediction is in accord with the JLab data as well as with the results of the Lattice QCD, chiral perturbation theory and KM15-fit. Our fit functions well define most of the JLab data in the interval $$ Q^2\in [0,0.4]$$Q2∈[0,0.4] GeV$$^2 $$2, while the Lattice results suffer from large uncertainties in this region. As a by-product, some mechanical properties of the nucleon like the pressure and energy density at the center of nucleon as well as its mechanical radius are also calculated and their results are compared with other existing theoretical predictions.

scholarly journals FERMIONS FROM PHOTONS: BOSONIZATION OF QED IN 2+1 DIMENSIONS

1994 ◽  
Vol 09 (27) ◽  
pp. 4669-4700 ◽  
Author(s):  
A. KOVNER ◽  
P.S. KURZEPA
Keyword(s):  
Perturbation Theory ◽  
Vector Potential ◽  
Energy Momentum Tensor ◽  
Lorentz Invariance ◽  
Hamiltonian Formalism ◽  
Momentum Tensor ◽  
Regularization Procedure ◽  
Local Polynomial ◽  
Definition Of ◽  
Chern Simons

We perform the complete bosonization of (2+1)-dimensional QED with one fermionic flavor in the Hamiltonian formalism. The Fermi operators are explicitly constructed in terms of the vector potential and the electric field. We carefully specify the regularization procedure involved in the definition of these operators, and calculate the fermionic bilinears and the energy-momentum tensor. The algebra of bilinears exhibits the Schwinger terms which also appear in perturbation theory. The bosonic Hamiltonian is a local, polynomial functional of Ai and Ei, and we check explicitly the Lorentz invariance of the resulting bosonic theory. Our construction is conceptually very similar to Mandelstam’s construction in 1+1 dimensions, and is dissimilar from the recent bosonization attempts in 2+1 dimensions, which hinge crucially on the presence of a Chern-Simons term.

scholarly journals Energy-momentum tensor for scalar fields coupled to the dilaton in two dimensions

1999 ◽  
Vol 59 (6) ◽  
Author(s):  
Fernando C. Lombardo ◽  
Francisco D. Mazzitelli ◽  
Jorge G. Russo
Keyword(s):  
Energy Momentum Tensor ◽  
Scalar Fields ◽  
Momentum Tensor ◽  
Two Dimensions

REMARKS ON THE MODEL WITH LOCAL U(1)V×U(1)A SYMMETRY IN TWO DIMENSIONS

1991 ◽  
Vol 06 (14) ◽  
pp. 1291-1298 ◽  
Author(s):  
YOSHIYUKI WATABIKI
Keyword(s):  
Energy Momentum Tensor ◽  
Central Charge ◽  
Axial Vector ◽  
Local Symmetry ◽  
Momentum Tensor ◽  
Two Dimensions ◽  
Global Symmetry ◽  
Supersymmetric Extension ◽  
Commutator Algebra ◽  
Local Vector

We investigate a 2-dimensional model which possesses a local vector U (1)V and axial vector U (1)A symmetry. We obtain a general form of Lagrangian which possesses this local symmetry. We also investigate the global symmetry aspects of the model. The commutator algebra of the energy-momentum tensor and the currents is derived, and the central charge of the model is calculated. Supersymmetric extension of the model is also studied.

scholarly journals ENERGY-MOMENTUM TENSOR IMPROVEMENTS IN TWO DIMENSIONS

1996 ◽  
Vol 10 (13n14) ◽  
pp. 1499-1506 ◽  
Author(s):  
S. DESER ◽  
R. JACKIW
Keyword(s):  
Scalar Field ◽  
Energy Momentum Tensor ◽  
Momentum Tensor ◽  
Two Dimensions ◽  
Conformal Anomaly ◽  
Gravitational Coupling ◽  
Two Dimensional

We discuss some aspects of the two-dimensional scalar field, considering particularly the action for the conformal anomaly as an “improved” gravitational coupling, and the possibility of introducing a dual coupling, which provides a “chiral” energy-momentum tensor improvement.

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