120170788
Nonlinear gauge fixing with auxiliary fields
We study renormalizability of gauge theories in nonlinear gauges with the help of auxiliary fields. We show that the auxiliary-field formulation is particularly helpful in understanding the divergence structures in the nonlinear gauges. A quadratic gauge-fixing choice in non-Abelian gauge theory in general induces quartic ghost terms. We show that there can exist various Becchi-Rouet-Stora-invariant Lagrangians involving quartic ghosts. However, renormalizability only selects out the Lagrangian which respects the global invariance corresponding to the original gauge group.
120503298
Systematic expansion for compact QED near weak coupling
39204644
Thermal Operator and Cutting Rules at Finite Temperature and Chemical Potential
In the context of scalar field theories, both real and complex, we derive the cutting description at finite temperature (with zero/finite chemical potential) from the cutting rules at zero temperature through the action of a simple thermal operator. We give an alternative algebraic proof of the largest time equation which brings out the underlying physics of such a relation. As an application of the cutting description, we calculate the imaginary part of the one-loop retarded self-energy at zero/finite temperature and finite chemical potential and show how this description can be used to calculate the dispersion relation as well as the full physical self-energy of thermal particles.
123610301
The hamiltonian structures of the KP hierarchy
Abstract We obtain the two hamiltonian structures of the KP hierarchy following the method of Drinfeld and Sokolov. We point out how the second structure of Drinfeld and Sokolov needs to be modified in the present case. We briefly comment on the connection between these structures and the W 1+∞ algebra.
18810830
The sTB-B hierarchy
Abstract We construct a new supersymmetric two boson (sTB-B) hierarchy and study its properties. We derive the conserved quantities and the Hamiltonian structures (proving the Jacobi identity) for the system. We show how this system gives the sKdV-B equation and its Hamiltonian structures upon appropriate reduction. We also describe the zero curvature formulation of this hierarchy both in the superspace as well as in components.
119380448
DYNAMICAL SUPERSYMMETRY
We show, in a simple quantum mechanical model, how a theory can become supersymmetric in the presence of interactions even when the free theory is not. This dynamical generation of supersymmetry relaxes the condition on the equality of masses of the superpartners which would be of phenomenological interest.
16528412
Anomalous magnetic moment of electron in Chern–Simons QED
Abstract We calculate the anomalous magnetic moment of the electron in the Chern–Simons theory in 2+1 dimensions with and without a Maxwell term, both at zero temperature as well as at finite temperature. In the case of the Maxwell–Chern–Simons (MCS) theory, we find that there is an infrared divergence, both at zero as well as at finite temperature, when the tree level Chern–Simons term vanishes, which suggests that a Chern–Simons term is essential in such theories. At high temperature, the thermal correction in the MCS theory behaves as 1 β ln βM , where β denotes the inverse temperature and M , the Chern–Simons coefficient. On the other hand, we find no thermal correction to the anomalous magnetic moment in the pure Chern–Simons (CS) theory.
17283472
Large gauge Ward identity
Abstract We study the question of the Ward identity for ` large' gauge invariance in 0+1 dimensional theories. We derive the relevant Ward identities for a single flavor fermion and a single flavor complex scalar field interacting with an Abelian gauge field. These identities are nonlinear. The Ward identity for any other complicated theory can be derived from these basic sets of identities. However, the structure of the Ward identity changes since these are nonlinear identities. In particular, we work out the ` large' gauge Ward identity for a supersymmetric theory involving a single flavor of fermion as well as a complex scalar field. Contrary to the effective action for the individual theories, the solution of the Ward identity in the supersymmetric theory involves an infinity of Fourier component modes. We comment on which features of this analysis are likely/unlikely to generalize to the 2+1 dimensional theory.
15524658
Finite Temperature and Large Gauge Invariance
In this talk, I will sumarize the status of our understanding of the puzzle of large gauge invariance at finite temperature.
115527023
On the energy-momentum tensor in non-commutative gauge theories
We study the properties of the energy-momentum tensor in non-commutative gauge theories by coupling them to a weak external gravitational field. In particular, we show that the stress tensor of such a theory coincides exactly with that derived from a theory where a Seiberg-Witten map has been implemented (namely, the procedure is commutative). Various other interesting features are also discussed.
118370691
Infrared chiral anomaly at finite temperature
Abstract We study the Schwinger model at finite temperature and show that a temperature dependent chiral anomaly may arise from the long distance behavior of the electric field. At high temperature this anomaly depends linearly on the temperature T and is present not only in the two point function, but also in all even point amplitudes.