120009559
The Witten index at finite temperature
Abstract It is shown that the Witten index for a supersymmetric theory always vanishes at finite temperature and the thermal vacuum has nonvanishing energy supporting the earlier conclusion of Das and Kaku that supersymmetry is spontaneously broken at finite temperature. In a simple supersymmetric model it is shown that the supersymmetry charges fail to annihilate the thermal vacuum and the goldstino states are constructed explicitly.
120503298
Systematic expansion for compact QED near weak coupling
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.
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.
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.
119355685
Forward scattering amplitudes and the thermal operator representation
We develop systematically to all orders the forward scattering description for retarded amplitudes in field theories at zero temperature. Subsequently, through the application of the thermal operator, we establish the forward scattering description at finite temperature. We argue that, beyond providing a graphical relation between the zero temperature and the finite temperature amplitudes, this method is calculationally quite useful. As an example, we derive the important features of the one-loop retarded gluon self-energy in the hard thermal loop approximation from the corresponding properties of the zero temperature amplitude.
118968179
Light-front Schwinger model at finite temperature
We study the light-front Schwinger model at finite temperature following the recent proposal in \cite{alves}. We show that the calculations are carried out efficiently by working with the full propagator for the fermion, which also avoids subtleties that arise with light-front regularizations. We demonstrate this with the calculation of the zero temperature anomaly. We show that temperature dependent corrections to the anomaly vanish, consistent with the results from the calculations in the conventional quantization. The gauge self-energy is seen to have the expected non-analytic behavior at finite temperature, but does not quite coincide with the conventional results. However, the two structures are exactly the same on-shell. We show that temperature does not modify the bound state equations and that the fermion condensate has the same behavior at finite temperature as that obtained in the conventional quantization.
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.
18666187
Topics in Finite Temperature Field Theory
We discuss a few selected topics in finite temperature field theory.
119273464
Thermal operator and dispersion relation in QED at finite temperature and chemical potential
Combining the thermal operator representation with the dispersion relation in QED at finite temperature and chemical potential, we determine the complete retarded photon self-energy only from its absorptive part at zero temperature. As an application of this method, we show that, even for the case of a nonzero chemical potential, the temperature dependent part of the one loop retarded photon self-energy vanishes in (1+1) dimensional massless QED.